Apartments for rent, convenient to downtown. Inquire within.
"We're talking about a higher order of reality... The world they come from, the world I come from, has...more of everything. I don't think you understand yet; the light of Heaven would slash open your corneas. The music of Heaven would puncture your eardrums and drive you insane. The air of heaven would burst your lungs and boil your blood. Only spirit can bear Heaven's touch."
The Manor in Noir: Said to be be "between France and Spain" (Protip: It's not Andorra), but Kirika gets there by walking from Paris. Its entirely normal (for rural areas in western European countries) landscape—it has fields of grapes and is covered with Roman ruins—manages to come across as profoundly unsettling even in bright sunlight. The main building seems to be bigger on the inside and is set over an active volcano.
Hell's Gate in Darker Than Black is full of Not of This Earth weirdness, the geography constantly shifts, Reality Is Out to Lunch, and, generally, there are very good reasons the scientists studying it have mostly abandoned manned missions in favor of sending in robots. As an added bonus, its appearance in the middle of Tokyo was accompanied by an Alien Sky covering the entire Earth and people suddenly becoming superpowered sociopaths. Said "sending in robots" consists of sending in a robot with a camera and having a full room of people watch the video stream and write down everything they see, because even through the video, everyone sees something different.
The Dark Ocean, a place populated by something that is either an Eldritch Abomination that can take the form of a Digimon and are suspiciously called the Digi-Deep Ones and serve a master that is suspiciously similar to Cthulhu, Digimons whose designs are heavily influenced by the Cthulhu Mythos (Named Dragomon in the card game but not in the show), or Cthulhu and his minions making a Lawyer-Friendly Cameo. It was stated that The Dark Ocean is a separate Dimension from the other two established dimensions.
Wherever the Hell it was Etemon ended up in after his first defeat in Digimon Adventure.
The world where the kids get sent to because Oikawa screwed up the card order
What happens to the Digital World after the Dark Masters are defeated
The inside of the D-Reaper's mass bubble when it invades Earth. It goes from a giant bunch of melted buildings and electronics and a few sidewalks to a liquid-like gooey landscape of pure pink and red evil all around. Not only that, but the digital world certainly qualifies when the D-Reaper has taken over and turned everything into a rather disturbing, apocalyptic-looking war zone.
And the world created by Mephistomon in Battle of Adventurers. It was ruined city with random vehicles suspended in the sky, everything was a shade of red, you could float around, and while it appeared submerged in liquid you breathe and talk normally.
Heaven and Hell in Ah! My Goddess both use and avert this concept. On the one hand, both are realms that exist in twelve-dimensions, far more than the normal humans of Earth can ever hope to perceive. However, due to their complete inability to perceive what they are not perceiving, the sheer alien quality of the two realms is completely lost on humans.
The End of Evangelion gave us the Sea of LCL, "a place with no AT-Field, where individual forms do not exist; an ambiguous world where you cannot tell where you end and others begin; a world where you exist everywhere and yet you exist nowhere, all at once". Its freaky nature is perfectly illustrated by the scene where Rei pulls out her hands out of Shinji's chest with absolutely no signs of injury on him note Though most viewers will be distracted by the fact that both of them are naked and she is sitting on top of him, straddling his waist during the entire dialogue...and their crotches appear to be physically merged with no sign of their...ehm, private parts. It's not a Dream World in that the place only exists in the shared reality between Rei, Kaworu and Shinji. The Sea of LCL is actually Primordial Earth after Rei had returned every living being in existence back to its most basic form. All Souls are now one with Rei and/or Kaworu, the Mother and Father respectively of every living being on Earth. So in said Reality of Rei, Kaworu, and Shinji it was basically the Entire World at the moment. Or maybe it was all concepts of Reality, depending on your interpretation of what the bloody hell was going on.
The Distortion World in the manga and anime adaptions of Pokémon is this to the core, due to not having the limitations that the video game versions has. Most notable is the random gravity for different areas, and, of course, Giratina.
The so called 'closed spaces' in Haruhi Suzumiya can be considered a form of this.
The entire country of Amestris is a subtle version of this. The Xingese characters notice that alchemy in Amestris has something distinctly off about it, and a creepy vibe seems to ooze from the ground and tickle their chi-sense. This is because Amestrian alchemy, which draws tectonic energy from the earth, is being suppressed by a massive system of pipes and underground tunnels. Amestrian alchemy can be completely disabled by Father at will, making him theoretically invincible. The whole system is derailed by a countermeasure based on Xingese alkahestry devised by Scar's brother before the series even started. Once Scar puts the plan into effect Amestrian alchemy becomes much more powerful than before.
In addition, there's the inside of the Gate, ("It's awful!") and the inside of Gluttony's stomach, which is a failed Gate somewhere "between reality and the real Gate".
Hell in Hell Girl is this, and it is deliberately designed for personalized Mind Rape.
Tsukuyomi and the Living Corpse Reincarnation realm, also some genjutsu are capable of projecting this type of location from Naruto.
Tokimi's realm in Tenchi Muyo!. Its a floating temple-like thing in the middle of nowhere in the universe. outside of it, its got a twisted, planet thing with a Space Whale. Her presence fills the room, but she is not there. And that's only in the third dimension. Each dimension up is so much more complex that a being from a lower dimension cannot comprehend. and there are a lot of them.
The whole point of the Nausicaä of the Valley of the Wind movie is that the Sea of Decay / Toxic Jungle is not this, unlike most characters think, and that it actually functions as a natural "cleanup" facility that filters all toxins from the world and creates a pure, healthy environment underneath that even supports regular vegetation.
The titular Psyren is Earth in the future with a membrane that disables all electronics, filters out sunlight, and saturates the atmosphere with psychic energy, awakening latent powers in the inhabitants and Drifters. The membrane is a fragment of an Eldritch Abomination named Quat Nevas, who devours the life force and PSI from planets after cultivating it this way.
YuYu Hakusho has the Demon World and the inside of the creature Itsuki summoned up to eat Kuwabara, Kurama,and Hiei. Come to think of it, almost anywhere other than Earth or the Spirit World count as this.
The town of Kurôzu-cho in Uzumaki becomes this over the course of the story as the curse of the spiral takes over. Roads leading out of town take travellers back in again, roads and houses begin to line up into a spiral shape, and beneath the lake lies a twisted underworld that's even stranger.
The city of Vanity from the short-lived Aztek series was implied to be one as well. It was a Wretched Hive that was worse than Gotham, full of a strange psychic malaise that turned two Captain Patriotic heroes into Nineties Anti-Heroes. It was implied that the town founders were all mad and used principles of sacred geometry to make the city utterly bent.
Let us not forget Arkham Asylum. The place gets destroyed regularly, yet somehow always magically comes back and it has a tendency to drive people completely batshit insane just by being there. When you remember these facts one kind of has to wonder why the city of Gotham thinks sending already insane supervillans there will make them better.
The 90s Doom Patrol had a benign one in the form of Danny the Street.
In the Marvel Universe , The Thanos Imperative introduced an entire freaking parallel universe as an Eldritch Location. It all began when somehow, somebody killed death and allowed Life to grow unrestrained. Now the entire universe is under the influence of Elder Gods and, using the Fault that has opened up in the MU, they are now intent on corrupting the rest of reality.
Quasar: I'm Protector Of The Universe. But how am I supposed to protect it from another universe? Planets, stars, whole galaxies that want to crush us all. I asked what's the worst that could happen. This is my answer.
Johnny's house in Johnny the Homicidal Maniac. It's implied the house grew its own Torture Cellar, and that the place is gradually expanding in order to take on more victims as Johnny grows increasingly insane and murderous. The Wall Johnny has to 'feed' also moves around the house, starting out at ground level and eventually finding its way down into the cellars.
Dungeon Keeper Ami features several levels of this. First, there are dungeons, with both a population of monsterous horrors and a corrupt magic that activly and visibly sculpts the landscape. In extream cases, this means into places not dissimilar from a nightmare. Then there are the temples dedicated to dark gods, which never seem to be perfectly silent, and which have even more horrific archetechture. Then there is the gladatoria arena of Azzaratha, which apparently supports a literal endless pit...
Evangelion: The Rite of Spring makes the battles with the Angels even more disturbing, as it moves the fight settings to Eldritch Location pocket universes. Kaworu and Rei's secret room in the theater may or may not count, but it certainly seems to defy the laws of nature. Really only to be expected for a story that's essentially Neon Genesis Evangelion meets Puella Magi Madoka Magica in art school.
The Emiya Clan basement is the equivalent of an epic dungeon crawler. It's basically where they throw all the junk they accumulate that is too dangerous or unstable to use. It's also where they lock any Eldritch Abomination that is too hard to destroy. Put two and two together and you get something along the lines of Moria.
The Powers Of Harmony has the Hollow Shades, a forest of massive trees, which was corrupted by Nightmare Moon a thousand years ago. The lingering magic doesn't affect ponies, but has mutated all the wildlife into massive Star Beasts (like the Ursa Major).
Queen Of All Oni: The vision Jade has of the lost city of the Shadowkhan implies this about it. For bonus points, the scene describing it has a very Lovecraftian feel to it.
It's commented several times that the Vault of Endless Night cavern is far too large to naturally exist under Mexico City and go unnoticed; characters on both sides agree that it must be a result of the place's inherent magic warping reality.
Film
In Labyrinth, Sarah's final showdown with Jareth occurs in a place that was designed by M.C. Escher.
Tiny in comparison to most examples, but the titular sauna in AJ Annila's Surreal Horror indie Sauna is a piece of Sinister Geometry that defies all definition, and has a habit of swallowing people whole, or sending them out...different. A common theory makes it the gate to Hell.
The apartment building in Ghostbusters certainly applies, given what it was designed for. The dimension one of the refrigerators opens onto counts as well.
In Event Horizon, the dimension that the gravity drive took the titular ship into is summed up as "Hell", but from what's hinted, Hell is pretty fuckin' warm and fuzzy compared to what actually lies beyond the portal.
If you think about it, Toontown in Who Framed Roger Rabbit? is an Eldritch Location in its context. All that stuff may be normal in cartoons, but in the middle of the real world it's bizarre to say the least. Alien Geometries? You bet. For example, the building you're in becomes higher than all the surrounding ones if you're in danger of falling from it and look down, simply because it's a trick used by animators to make it look more like the perspective is from really high up.
The room in 1408. As Samuel L. Jackson's character insists, there are no ghosts, it's just "an evil fucking room". Yes, the Eldritch Location is itself the Eldritch Abomination.
In Bram Stoker's Dracula, normal laws of physics don't quite seem to apply in Castle Dracula, most notably seen when Harker opens a perfume bottle that starts dripping upwards into the ceiling. For extra creep factor, the castle itself vaguely resembles a ghoulish figure crouched on a cracked throne.
Yellow Submarine - The Beatles' Liverpool abode is a grim little wharfside hovel on the outside - inside it's a cavernous palace with endless corridors that open into scenes from King Kong, Magritte paintings, and the like, while various outsize objects, inanimate and otherwise, run in and out of doors when no one's looking. The places they visit on their journey are similarly extradimensional.
The hospital in Grave Encounters. The trapped ghost-hunting team manages to bust open the front door, only to reveal another hallway. Same for an emergency exit. Later, a staircase promising rooftop access instead leads to a blank wall, and underground tunnels that should have had turn-offs for traversing between buildings instead turns into a single, Endless Corridor. Until the end, anyway.
The Mayflower department store in Mirrors has become this thanks to Demonic Possession and being an otherworldly prison for the ghosts of those who have died there. While the store itself doesn't have any strange geometry (though being burned out it is quite creepy), The Maze of tunnels beneath it is rather unsettling and the Demonic Possession allows for many strange visions, images, and effects throughout it, including some very disturbing All Just a Dream/That Was Not A Dream sequences.
Literature
In The First Law Trilogy The House of the Maker qualifies. A massive, mysterious structure that nobody has been in for thousands of years that completely defies physics, such as the ability to ascend floors without the use of stairs or any other means.
The world described in the incomprehensible Codex Seraphinianus.
Lovecraft's writings have several of these in addition to R'lyeh. These include the subterranean N'knai, the planet Yuggoth with its black towers and rivers of pitch, and the Outer Void that exists beyond our four-dimensional space and is the dwelling place of the Outer Gods. The Dreamlands may also count, as it's apparently a separate plane of existence that shares a connection with our world.
The Plateau of Leng, that may exist somewhere in the Himalayas, in Antarctica, or in the Dreamlands, or possibly in all these places.
Wherever (or whatever) it was that could be seen from Erich Zahn's balcony, and drove him to compose such music. Probably extends somewhat to the entire street, given the narrator's later incapacity to locate it.
The lost city of Carcosa, "where black stars hang in the heavens; where the shadows of men's thoughts lengthen in the afternoon, when the twin suns sink into the lake of Hali. . ." From Robert Chambers's The King in Yellow, which he borrowed from Ambrose Bierce's "An Inhabitant of Carcosa". Later used by Lovecraft and his successor, August Derleth.
In the Incarnations of Immortality series, the raw, unmade substance from which Clotho spins thread is deep within one of these. Trees start to become geometric abstractions, and she walks on a path which goes upside down, and pretty much everything breaks down as she reaches the area from which she must collect the raw material from which to spin her threads.
Also the castle that Susannah's doppelganger visits in her dreams is described as an eldritch location filled with unknown horrors in the machinery-filled rooms below, on the edge of End-World which is portrayed as an even worse Eldritch Location with a pulsating red light coming from it.
More King: From A Buick 8 theorizes that the eponymous car is a portal to such a place. Possibly subverted, as the... things that come out of the car seem to find humans just as horrible and terrifying as we find them.
The room in 1408. Both the short story and the movie are insistent that there's no ghosts.
The standing stones on Ackermann's field in N..
As mentioned above: Giant country and The Land of Dreams in The BFG. They're somewhere on Earth, but they've never been seen by man before the events of the book, no one had even suspected they may exist, and not even the BFG, who lives in the land of Giants, knows where it is. (He gets there by homing instinct.)
The Nevernever. In size, it is to Australia what Earth is to the Rhode island, and the laws of physics just don't work the way they do in our world. In fact they almost never do.
Demonreach, introduced in Small Favor, is a less alien but no less powerful site. Aside from being the source of a massive dark energy ley line, it is also self-aware and does not show up on any maps because ships disappear around it and aircraft navigation goes out close to it. In Cold Days it is revealed to be a prison for Eldritch Abominations with skinwalkers being only in Minimum Security. And Harry's connection to the place sensed in Small Favor was the possibility where he become the Warden of the entire island, with the power to free everything inside on a whim.
Brian Lumley's Necroscope novels have the vampire world which is home to a White Hole that plunged half the planet into and towered eternal night, and the Möbius Continuum.
In Dan Abnett's Eisenhorn series, there is a similar place; the Alien Geometries is taken to its describable extreme (for instance, there are triangles that clearly have more than 360 degrees internally) and every little thing is another impossibility made possible. Most of those who enter lose their minds in a short while.
And then there's the City of the Saved: the result of the fusion of the ultimate sum of all human technology in all of history merged with a goddess from the end of time. What does that equate to? A galaxy-widesentient space station, containing all humans to ever exist in immortal, perfect bodies, including all hybrids and virtually all fictional characters ever, permanently anchored at the edge of the Universe in its last nanosecond before the birth of the next. Unfortunately, there was an infection of something that came out of the other end, and now the normally very pleasant City's infected with nightmarish industrial wastelands specialized in human experimentation. It's as horrific as it sounds.
Most Simon R. Green novels feature at least one of these, if not more.
Algernon Blackwood's "The Willows" takes place in such a setting. A possibly sentient setting, no less.
Death's Domain is definitely this. While it appears normal at first glance, the house is much Bigger on the Inside than it appears, there are a wide variety of shades of black, a peculiar blue glow appears on the horizon, the mountains can never be reached, time does not pass for mortals, and peculiar and unsettling shadows appear.
And in The Light Fantastic, when Rincewind and Twoflower pay Death a visit, they use a picture-taking imp to take a picture. The imp sees what is really there, is confused at the location ("Where ARE we? Three bloody years at F8 if you ask me.") When they look at the picture later, it is extremely unsettling and was NOT remotely what the visitors saw.
Lancre contains a few places like this, including the portal to the elves' world from Lords And Ladies and the "gnarly" ground in Carpe Jugulum.
Inverted in the Science of Discworld books, where the mundane physics of the Roundworld universe — i.e. our own — seem like this trope to the wizards, who are used to things running on narrativium rather than rules.
The setting of Full Tilt is superficially an Amusement Park of Doom, but the "rides" expand into mini-worlds, ranging from a burned-out slum to a mock-up of ancient Egypt to an asteroid field made of Pintos that explode when touched. According to throwaway dialogue from its creator, it's less "real" than our own world, but it will become more real as more and more people are drawn into it, and all other worlds will become mere shadows.
The Duat in The Kane Chronicles. It's the expansion pack version of the Underworld from the Percy Jackson and the Olympians series by the same author (and canonicallyin thesame universe). There are the shallower regions where we find the Halls of Maat, the center of Order in the universe and stronghold of the Egyptian Gods. And, presumably, the region controlled by the Olympians for their underworld and imprisoning the odd Eldritch Abomination. But then there are the deep reaches of the Duat, where there are vast gulfs even the gods fear to tread and Apophis lurks. This corresponds to the reaches where the Olympians tossed the remains of Kronos.
In Dean Koontz's Seize the Night, military scientists have found a way into some kine of parallel universe of red skies and black, fungus-like trees. The protagonists initially believed the scientists had been building a time machine to the future. Actually, they may have opened a doorway to Hell - so to speak. One of the characters later postulates that our ideas of Heaven and Hell may have come from genuine mystics who were able to glimpse alternate dimensions, some incredibly alien to our own.
"That's not the future. That's . . . sideways."
Pretty much everywhere in the Dr. Seuss books, especially "Oh, the Places You'll Go!"
Te land of the elves from the Serrated Edge series fits, at least those parts not formed by a sufficiently strong will into some definite state. As with all travels into the realms of the Elves in this series, it is EXTREMELY hazardous to enter an unformed region without adequate (usually magical) assistance, and anything one can imagine (and many things one would rather not) may be found there. Entering with an unfamiliar Elf is actually MORE dangerous, because an untrained mortal is effectively incapable of distinguishing the Seelie (relatively benign) Elves from the Unseelie (Always Chaotic Evil) Elves until it's FAR too late.
The Darke Halls in Septimus Heap are described as this, having the power of driving people to madness.
A Song of Ice and Fire has the House of the Undying, home of the Warlocks of Qarth. It only appears once, but as soon as she starts walks through it, Daenerys realises that the path she's taking should be impossible due to the positions of the building's outside walls. This is in addition to the various visions and illusions she sees while inside. It's unclear whether there is anything special about the building itself, or if it's simply the power of the its inhabitants that causes these effects, or what the intentions or morality of the Warlocks/the House/the Undying really are, since the Undying give Dany cryptic visions and prophecies and then try to eat her, but certain hallucinations she receives seem to be trying to draw her to some different eventuality from this, and the warlock is furious that she set fire to the place as she tried to escape.
The Perry Rhodan setting has seen its share of these. A prominent example used as the backdrop for basically an entire arc was the Land in the Deep ("Tiefenland" in the original German) — an artificial construct built into the void between the universes, a light-year across but with a nigh unsurmountable ceiling only a couple thousand and change meters above its surface, populated by all manners of weird lifeforms whose ancestors were usually recruited from all over the universe millions of years ago... And then the subtle influence of the Deep eventually proved hostile to lifeforms from "above", with the results of overexposure resulting in anything from death (often via petrification) to corruption into antagonistic "grey life". By the time the protagonists Atlan and Jen Salik finally ended up there, things had already gone much as one might expect.
Robert Holdstock's Rhyhope Wood saga, starting with Mythago Wood. The titular wood is Bigger on the Inside, stretching far back into the mists of pre-literate human history and mythology. It's also something of a Genius Loci, with ways to prevent those how don't understand it well from penetrating beyond the outer fringes.
The Q Continuum, home of the (supposedly) omnipotent and omniscient species known as the Q (and also sometimes used as a name for the species itself). When we saw it on-screen in two Voyager episodes, it appeared first as a gas station on a desert highway and then as a battlefield from the American Civil War (when the Q were fighting their own civil war). This was probably done due to the show's budget constraints, and was justified by explaining that the Continuum cannot be perceived by a humanoid as it truly exists, and thus it will appear as an analogue from the viewer's culture. In one TNG novel, the android Lt. Commander Data is taken to the Continuum and forced to perceive it in its true form. This causes him to shut down as the result of the sensory overload.
Another Star Trek example is the Next Generation episode "Remember Me," in which an experiment with warp bubbles goes wrong and sucks Dr. Crusher into some kind of parallel dimension shaped by the thoughts she was having at the moment she was trapped. It appears to be a replica of the Enterprise, except all the other crew members start vanishing one by one and no one except Crusher remembers they existed. Then it gets even worse. Dr. Crusher activates a view screen and sees a "warp energy field" encasing the ship. After establishing that there is no penetrating the field, she asks the computer to define the universe. It replies, "THE UNIVERSE IS A SPHEROID REGION 705 METERS IN DIAMETER". The computer says that there is nothing outside of the ship.
Just before asking that question, Dr. Crusher asked the computer the diameter of the energy field surrounding the ship was. The computer replied that it was 715 meters in diameter. That is not a typo; the field had shrunk 10 meters between questions, and continued to shrink throughout the episode.
Crusher spends most of the episode thinking she's going insane, and with everyone around her apparently certain she is (until they disappear, that is). The turning point occurs when, after exhaustive tests show nothing wrong with her brain, it finally occurs to her: "If there's nothing wrong with me, maybe there's something wrong with the universe."
From Star Trek: Voyager, there's Fluidic Space. Its an extradimensional realm where there are no stars or planets or anything else of mass. Everything is just a organic soup there. The only life form that has ever been encountered there is the equally eldritch Species 8472, which the Borg consider the apex of biological life.
The Black Lodge from Twin Peaks. A world where people speak backwards, little people dance to jazz music and cream corn is used as a form of currency. The lodge itself is really just a series of identical rooms with red curtains and a zig-zag patterned floor. Or it could be that it is just the same room repeated over and over.
Heaven in Supernatural. Every heaven is basically just the best moment of your life over and over again.
Einstein's Realm in Farscape. Reachable only by wormhole, it acts as a meeting ground between the representative of the True Ancients and anyone knowledgeable enough to be dangerous to them: it's basically an iceberg floating in an ocean of wormholes beneath a pitch-black sky. Due to Einstein's influence, physics tend to behave quite strangely here, and Crichton often ends up speaking to long-dead individuals from his past and tumbling into Unrealized Realities.
Doctor Who is FULL of these. The TARDIS is one in living,alleged ship form. The Doctor has visited some quite notable ones, like The Impossible Planet (prison of a being that claims to be the ultimate source of evil in the universe), and the Zeta Minor (visited during The Planet of Evil) where strange beings lurked and tried to prevent catastrophe caused by removing material from the place. The Doctor also visited to near the end of the universe (finding desperate humans trying to flee from vampire-like Future Kind), and even the extrauniversal E-Space, multiple parallel universe, and once simply PARKING OUTSIDE REALITY. Perhaps the most Eldritch of all Eldritch Locations, House, a sentient asteroid living in a pocket dimension that fed on TARDISes.
The Valley of the Fallen Kings in Merlin. The first time we see it, it's revealed that the Crystal Cave, the source of all magic, is hidden in the valley. And is also a very good example of Good Is Not Nice, as it's perfectly willing to subject Merlin to Mind Rape and a chain of Self-Fulfilling Prophecies to teach him a lesson. Arthur constantly says that the Valley is harmless unless you're superstitious, but even he and the Knights avoid it if they possibly can.
The Dark Tower, very much so. In addition to the stories young knights are apparently told to scare them away from it, it is surrounded by an impenetrable forest that, in addition to being nigh impenetrable, reverses directions so you can only get out if you have help. It also looks rather terrifying and Queen Mab gives Merlin some rather disturbing advice:
Queen Mab: You must beware, Emrys. The Tower is not a real place. It is the heart's rest, the mind's deepest fear, the stillness in the hummingbird's eye.
And this was before we knew what it did to the people that the High Priestesses brought inside: it tortured them until the screams could be heard from twenty leagues away and then bound their spirit, leaving their body an empty vessel for another's will to inhabit. The process is nightmare-inducing, and we get to see it all from Gwen, the victim's perspective.
The kingdom of Hades of Greek Mythology, which was thought to be accessible by the Real Life River Acheron in Greece. Explorations therein have yet to show anything more interesting than fish. Not even zombie fish.
Older than Dirt: The Duat in Egyptian Mythology, which was believed to be simultaneously below the earth, behind both the west and east horizons, and above/inside the sky.
God's throne in Heaven is directly above everywhere on Earth. This is an obvious physical impossibility... except that God is beyond physics. Hell, being Heaven's inversion, likely has a similar explanation. God himself takes it a step further: he is described as omni-present, meaning that He can occupy all of space all at once and is just as present on Earth as he is in Heaven, the entire universe is an Eldritch Location for God Himself.
Norse Mythology has the Ginnungagap, Múspellsheimr to the "South" of that, Niflheimr to the "North," and pretty much any of the other Nine Worlds that isn't Miđgarđr(Midguard).
Roleplay
The Torn World from Dino Attack RPG, a mysterious, empty void where bricks go after they've been torn out of the Constructopedia. The dimension vaguely resembles space, but despite this, one can breathe reasonably well and there is gravity present (anyone who can't get a hold of a brick is likely to fall forever into nothingness). Also for some reason, no matter what kind of bricks are taken, they always break up into 1x1 pieces.
To a lesser extent, the Maelstrom Temple, which has a tendency to change its inner structure whenever your back is turned (making it very hard for one to find their way out), and it can create illusions to mess with your head.
Tabletop Games
Dungeons & Dragons has the Far Realm, but really, most of the planes qualify, doing stuff like having distance travelled depend on the amount of good deeds you do, or matter being shaped by thought. Every other plane has some kind of mythology-based logic to it (Ethereal and Astral transport mimics the real-world mythology for movement in Out Of Body experiences, the Heaven and Hell planes are exactly what they sound like, etc.). The only identifiable trait of the Far Realm is that none of it is identifiable, or even quantifiable in any way, shape or form. Simply entering it causes unavoidable Mind Screw to outright Mind Rape. Characters may sprout eyes on their palms (but not really), relive a hundred lifetimes in which their parents were Far Realm wights, or backwards speaking begin... Altogether unsurprising, as the Far Realm is based on the works and mythos of H.P. Lovecraft. The Far Realm represents the edge of reality, where the reality that mortal minds can grasp transforms into something...different.
Terra Incognitae in Scion are all the mysterious islands and lost worlds described in mythology. You can't get to them unless you yourself are mythological (i.e., have a Legend score).
Changeling The Lost gives up the Hedge, the mysterious otherspace between Earth and Faerie. Not only does it seem to map roughly to Earth in size, but it could technically be considered four-dimensional, as there's always going to be a direction that's just "towards Faerie."
Pretty much everywhere outside of Illusion in Kult. Weird geoscapes are the least of your worries. Gaia is the primal world where even the earth can get hungry and swallow people, Metropolis is a city filled with lunatics and Inferno is a classic hell.
The Wyld, in which reality as we know it pretty much stops working. Divided into the Bordermarches, the closest regions to normal reality, which are only mildly weird, the Middlemarches, where the laws of physics cease to be reliable and movement and distance are based more around narrative conventions than concrete measurements, the Deep Wyld, where reality is officially Out To Lunch, and the Pure Chaos, which isn't so much a location as it is the unshaped, incoherent chaos outside of the universe.
And then there are the Shadowlands, sites of past atrocities and mass murder where the border between Creation and the Underworld is just a bit thinner. Regaining Essence is hampered (unless you're a creature of the Underworld, in which case it picks up by comparison), ghosts can get around more easily, and improperly buried bodies tend to rise as zombies.
Several of the Primordials/Yozis are this as well. Things like the local geography, physical laws, and even time flow are often at the whims of the Titan that is the world. The most notable are Malfeas (the Demon King/City whose body acts as the prison of his fellows, and consists of multiple layers that constantly change shape and correspondence, and all inexplicably have the green sun of Hell right above them), Cecylene (the Endless Desert who is accessible from every layer of Malfeas and always takes exactly five days to cross) and Autochthon (who needed to deliberately modify his world body to make it habitable; the deeper parts of it show the reason for this).
There are even a few places in Creation that work like this. One is the Well of Udr, overseen by the Dowager of the Irreverent Vulgate in Unrent Veils. It's a nexus of all possible dimensions where the strata of potential worlds collide and crash against one another, occasionally disgorging impossibilities. It's very tricky to get anywhere within its vicinity and hold onto your marbles, let alone stare into it. It's from here that the Dowager retrieved the Great Contagion.
The Elemental Poles, too, each of which is an unending font of elemental power. The trees at the Elemental Pole of Wood are infinitely tall.
The Umbra from the Old World of Darkness folds in itself any sort of alternative reality and other states of being. And one has to step sideways to reach it. Sideways to reality as a whole. Furthermore, different places in the Umbra have their own laws, and the further one gets from Earth, the weirder and more hostile, the worlds become, until the Deep Umbra is reached. Things are just plain wrong there. And very, very inhospitable for almost any type of earth-like life.
And then there's the Black Spiral. Depending on which game in the cobbled together setting you happen to be operating in, the Black Spiral is either in the Deep Umbra, the Dark Dreaming, the center of the Maelstrom, or is either a convergence or a place that has doorways to all three. Put simply, it's Hell, but of course it's not that simple and entire books have been dedicated to describing, expanding, contradicting and redefining what the Black Spiral actually is. There are even allusions that it is the dessicated husk of ancient Malfeas from Exalted. It breaks, reshapes and fundamentally corrupts anyone unlucky enough to find themselves there, and we're talking mentally, physically and spiritually, all at once. It is the home, seat of power, dying body and prison of the fundamental force of entropy in the setting's universe. One tribe of werewolves are called the Black Spiral Dancers. Guess what they do for an initiation rite?
The Shadow Realm of the New World of Darkness, is more a Dark World. But if you go deep enough, you get to the parts of the Shadow Realm taken over by lords among the Spirits, and then the rules disappear.
Aside from the mentions in the literature section above, everything in the Eye of Terror ends up this way, as well as the Maelstrom (basically a mini Eye of Terror that doesn't even have the decency of an explanation of how it started). Any place a Warp Rift is opened starts to slowly turn into one of these, and if the rift is left unchecked it can end up turning the entire planet into a Daemon World. And that's just what happens when a tiny fraction of the Warp leaks into the real world...
The Dark City of Commorragh, home of the Dark Eldar, is also an example, being an enormous collection of realms located inside the Webway (a network of warded tunnels in the Warp), linked together with portals. It's basically Escher on crack and populated entirely by sadistic murder-elves. To make matters worse, in some parts the wards that separate the Webway from the Warp have become weakened, leading to things like districts where shadows come to life and things from outside reality lurk.
Necron tomb worlds are examples of non-Warp related eldritch locations. The Necrons' mastery over science allows them to create spaces that follow a higher order of geometry than we're used to, resulting in things like buildings that are bigger on the inside.
Magic: The Gathering has locations associated with its resident Eldritch Abominations, the Eldrazi; in particular, a combination of solitude and proximity to the Eye of Ugin, which sealed the Eldrazi within the plane Zendikar, cost the planeswalker Sarkhan Vol his sanity.
In Nephilim, Selenim are capable of creating Realms, pocket universes that exist according to their will, which turn out like this trope.
Arkham Horror allows the players to visit the locations from H.P. Lovecraft's mythos, like the Plateau Of Leng, Yuggoth, and the R'lyeh.
Tropes
The Sugar Bowl is a strange form of this. It may be depicted as a genuinely nice place, or as it was in the article. However, there's no denying that a place with licorice trees and structurally sound buildings of candy would belong here.
The Clown Car Base also fits this trope in a way, especially when the trope is lampshaded, revealing it to be not just a perspective oddity, but a genuine physically disproportionate building.
A Dark World can function as an Eldritch Location when it's explicitly evil or "wrong", but a few morality neutral Dark Places are natural "night side" reality counterparts to our own.
Bacterian, the Big Bad of the Gradius series qualifies: He is a Genius LociHive Mind that uses psychic powers to control his fleets. Every time he's defeated, the pieces of him regenerate to form new Bacterians. Gofer, Venom, Zelos, and some other large Bacterians also qualify.
The Pfhor ship of Marathon seems to be mostly organic, with green liquid all over the place. The gravity is low, too. The creepy music doesn't help either. Marathon's game engine actually encourages non-Euclidean level design because of the way it implements overpasses. Several levels have passageways that pass through each other as an intentional Mind Screw, and some third-party mapmakers have taken it to a very confusing extreme.
Silent Hill features a weird variation of this trope through the eponymous town. Though its exact nature is very much up for debate, it appears to be abandoned and shrouded in fog, day and night come randomly, and a nightmarish "otherworld" version of the town lurks beneath the surface and can overtake you at any moment. The otherworld draws its form from people's minds, sometimes the protagonists and sometimes another character entirely; quite a few epileptic forests have grown from trying to explain it all.
Once the Devil's Machine is turned off, it's implied that Giygas might just be huge and dimension-warping enough to be not just an Eldritch Abomination, but one of these in his own right.
Way before that, Ness and Jeff get to visit Moonside, which also qualifies.
The various incarnations of the Lost Woods in the Zelda games: they either turn off your minimap, making navigation extremely difficult, or in Oracle of Seasons, one place is even completely off the map, not to mention the place where Like-Likes fall from the sky. In Ocarina of Time it's implied that anyone who isn't of The Fair Folk would tend to become hopelessly lost, eventually turning into skeletal imps doomed to haunt the forest forever.
The Legend of Zelda: Majora's Mask as a whole, the entire game, is made of this trope. The games's setting is a pseudo alternate dimension called Termina, and the fact that the game's titular villain is a reality warping, psychopathic eldritch abomination only makes it worse. Oh, and the closest thing you have to a mentor type character may or may not be a dimension hopping mastermind who planted Majora's mask on purpose.
Chzo is both this and an Eldritch Abomination, a pain elemental who satiates himself with tortured victims trapped inside his labyrinthine corridors for all eternity.
The interaction of Hyperspace and Pathspace in Immortal Defense produces one of these. From Pathspace, Hyperspace looks like a twisty path across a 2D plane, and from Hyperspace, Pathspace is the home of vindictive demigods who rain psychic death upon unwary travelers. The protagonist is one of these demigods.
The Adamantine Spire, a.k.a. the Adamantine Space Elevator. The weirdest part is that even when other people tried to recreate it using the same worldgen seed, it didn't show up. Current theories are that it's due to interference from old save data.
Fridge Horror: Considering what adamantine veins like the spire usually contain, it looks like whatever counts as Heaven in the Dorf 'verse is in for some serious Fun.
Some of the more convoluted succession forts such as Battlefailed become this. Battlefields had the temporally locked dwarves in the arena, Headshoots had the room outside of space, ect.
The Distortion World from Pokémon Platinum falls under this. Floating masses of land in a giant vortex, giant plants that sprout randomly out of nowhere, disappearing platforms, and waterfalls that float up are just a few features to be found. Not to mention that the only thing living in there is the Eldritch Abomination known as Giratina. Not to mention the immense Gravity Screw of the Distortion World. The waterfall isn't the only thing that goes the wrong way there; the Distortion World is the only place in the whole main series where you navigate by jumping onto those floating platforms and walking sideways.
It's an Eldritch Location and houses several Eldritch Abominations to boot. The discrepancy that crops up between the games is lampshaded and handwaved with a comment that the castle is "a creature of chaos." The castle can take many shapes and forms, picking and choosing when and if it wants to follow the laws of physics.
Hell, in the installment that gave us that Hand Wave (Castlevania Symphony Of The Night), the whole castle has an inverted duplicate revealed halfway through. You and the monsters fall towards and walk around on the ceiling. All the furniture is still on the floor. It is never explained why a second castle just appears out of the clouds, nor why it's upside down. And then there's the two mirrored split castles in Castlevania Harmony Of Dissonance, which are somehow both the extension of Maxim's will...
Both final levels of Kingdom Hearts 1 and 2. The one from the first game, appropriately titled The End Of The World, is basically the remains of any and every world destroyed by The Heartless, and the one from the second game, The World That Never Was is a dark city overrun by Heartless overlooked by the warped castle that is the headquarters of Organization XIII, and its moon is apparently "the heart of reality itself." In fact, the concept of the worlds makes them Eldritch Locations: They are apparently separated by barriers, but are described as sharing the same skies (for that last bit, what does ''Sora'' mean in Japanese?). Birth by Sleep Final Mix gives us a deeper look at the Realm of Darkness, where the Heartless originate from. The new Secret Ending also shows that not all worlds are destroyed when consumed by the darkness...
Persona 3 has Tartarus, an ever-changing tower that only exists during the Dark Hour, and acts as a pathway from the world of Death and the Collective Unconsciousness from which humanity's Shadows can manifest. FES adds the Abyss of Time as its inverted twin.
Persona 4 has rather the creepy TV World, which once again, is the Collective Unconsciousness being forced to manifest via the "mind" of mass media. Subverted in the True Ending, where lifting the final veil of deceit from mankind's heart turns the Collective Unconsciousness itself into the Ghibli Hills.
Strange Journey has the Schwarzwelt. It is effectively a void over Antarctica where demons appear, overwriting Earth with their own reality. The Investigation Team's mission is to analyze and nullify the Schwarzwelt before it can consume the entire world. The game over screen shows what happens if your character dies...it ain't pretty. The fun part is that the UN sent cameras into the Schwarzwelt during the planning stages...and nobody believed the results (one of them was a shopping mall). Turns out they were all accurate (but you don't want to eat the food in the shopping mall...).
Nocturne mostly takes place within the Vortex World, a chaotic, demon infested realm that the Earth reverts to when it comes time for a new world order to be decided. Naturally, it's up to you to shape it as you see fit. For bonus points, it's a truly literal form of Tokyo Is the Center of the Universe.
Everytime you fly through Bydo Dimension in R-Type, especially the Mind Screw territory of the final stages of Delta and, well, Final. To put in specific terms, the Bydo Dimension in Delta, which is depicted in the picture above, looks like a twisted version of our world with babies encased in crystals, upside-down buildings, huge strands of DNA, and a weird forest of Bydo Trees. The Bydo Dimension in Final is an abyss full of fluid inhabited by eyeballs and the creature implied to be the real source of the Bydo. The Bydo Tree forest bit also appears in Final as a hidden stage. There is also a stage in Final that takes place in a weird dimension where there is only the player, a slug Bydo named Nomemayer, and particles of light that can turn anything and anyone into a Bydo. And there's Anti-Space, a dimension created by some Bydo guys named Gridlock.
In the final level of D-Generation, what before looked like an ordinary office building (albeit with hyperactive security measures) suddenly turns into a bizarre surreal nightmare. Oh, hi there headless guy! Well that's an interesting fractal background!
The Fade, the place people (except dwarves) go when they dream, full of spirits and demons and doubling as Heaven, Hell and everything in between. Characters are trapped in their own "mini-Hells" (reflecting their own lives), the sky is full of floating mountains (heavily implied to be other, infinitely large hells) and the Black City is visible wherever you go.
And in the DLC Witch Hunt, Morrigan implies that beyond the Fade there are places that are even stranger where she's keeping her Demon Baby safe from her evil mom.
Amgarrak Thaig, the titular location of Golems of Amgarrak is definitely one, protected from the outside by a maze of shifting mist and having Lyrium Wells that were designed to phase-shift people into alternate versions of the Thaig in order to better safeguard its secrets.
The sequel brings us Kirkwall. Yes, that's right: the main setting. It's subtle, though; you can go through the whole game just thinking the whole place is a Crapsack City-State, but certain notes you find indicate that not only is the Veil unnaturally thin over the entire area, entire neighborhoods are constructed in the shapes of blood magic sigils, there are likely lakes of blood beneath the streets that still haven't dried, but demons are actively drawn to the place like flies to the point where they occasionally hunt non-mages because there's too much competition. And that's before you factor in Corypheus'corrupting presence from his Grey Warden Prison in the nearby Vimmark Mountains. It - or very nearby - is actually where the magisters entered the Black City (sacrificing hundreds of slaves in a blood ritual in the process) and were transformed, like Corypheus, into darkspawn, causing the Blights. Kirkwall is basically the Dragon Age verse's version of the Hellmouth....
The Primeval Thaig is definitely one, built by prehistoric Dwarves that worshipped a pantheon of deities, constructed using magic thus giving it some degree of Alien Geometry, posessing a unique form of Red Lyrium running throughout the structure itself and inhabited by creatures like the Profane that Varric claims were supposed to be myth. It was also the location where Hawke and company first encountered the Lyrium Idol.
In an older BioWare example, the Spirit World of Jade Empire is similarly weird.
Homeworld: Cataclysm's Beast is said to come from "Outside". In the titular fanfic, Outside is taken to mean the highest level of Hyperspace.
Final Fantasy XI has a few that qualify, and they all tend to follow the "islands floating in nothingness" style:
The Promyvion areas appear to be corrupted, shadowy versions of other existing areas, topped off with haunting music and freakish looking monsters.
The Walk of Echoes is an area of disconnected structures floating in nothingness. It pretty much exists outside of time, and Atomos himself can be seen in the sky at all times.
And also the recently added Provenance areas, which are described as being the place where the source of all life comes from.
The Dead Sea from Chrono Cross. It's the site of a massive Time Crash, where the canceled Bad Future from Chrono Trigger tried to reassert itself over Chronopolis. Waves of water, forever frozen in time, wash over the wreckage of the city, and at the heart is the Tower of Geddon, a conglomeration of locations from said canceled timeline haphazardly mashed together. Much later, you also go to the Darkness Beyond Time, where cancelled timelines are sent and where the Time Devourer lurks.
Its prequel Chrono Trigger already had the End of Time, the place where all possible time lines meet. As far as eldritch locations go, it's actually fairly harmless. The Updated Rerelease added a few more such as the Dimensional Vortexes, areas where time and space are essentially broken. The Darkness Beyond Time also makes an appearance.
In Wild Arms 2, the Encroaching Parallel Universe "Kuiper Belt" is one of the most terrifying examples yet.
In the original Phantasy Star series, the very Algol star system it takes place in is an enormous lock for a dreadful Sealed Evil in a Can. And the lock isn't exactly completely intact.
The titular planet in Albion looks like some alien world with primitive civilizations at first. Until it is revealed that it operates under completely different laws the Earth does. The fact that it's actually a sentient (benevolent) being, has something to do with it.
Chief among them is Outland. It was formed when the planet Draenor was torn apart by multiple interdimensional gateways being opened on the surface. It's now a continent with several different ecosystems, some of which are healthy and normal, or at least, as normal as the rest of this universe. However, the continent is surrounded by, rather than an ocean, an edge, and if you walk off it you fall into nothingness. It also has an Alien Sky, which is sunless but otherwise mysteriously normal in some zones, but looks like energy cascading through space in other places. In several places there are Floating Islands, some of which have water perpetually falling off them with no source. Other examples in the Warcraft universe:
The Maelstrom. A eternal whirlpool full of unstable energies surrounded by an eternal hurricane that was formed when the Well of Eternity was destroyed. The black dragon Deathwing used it as a portal back to Azeroth, almost causing the world to blow up. The constant attention of several powerful shamans is required to keep the world from falling apart through it.
Deepholm. It can be reached by flying into the Maelstrom. It is the home of earth elementals and other creatures native to the elemental plane, so it's not supposed to be comfortable to flesh-and-blood creatures like playable races. It is a massive cave with a rock-based ecosystem and rock pillars that float in the air. Most of the elemental planes are odd like this, but with another element in the place of rock.
Karazhan is a large black tower in the mostly empty Deadwind Pass. It was once home to Medivh, The Last Guardian, and sits atop a point where every ley line (think veins, but instead of blood it's magic) in the entire world intersects. Time itself gets lost within Karazhan, allowing visions of past, future and other worlds to pop in and out unexpectedly. One of Medivh's theories is that the Deadwind Pass was formed because someone would eventually build a tower there, rather than the tower being built where the Pass was. Also, there is an inverted Karazhan under the main one, and the main one exists in at least two parallel universes at once. Not to mentioned the odder features inside and around the tower...
The World of Mammon in Quest 64. The environment drastically changes with each transition, doors never lead to the same place twice, the sky is always the wrong the color, and the music is creepy as heck. The inhabitants are just as unnerving: among them are Living Statues that have more than a passing resemblance to the Weeping Angels. Of course, the entire place is the prison/domain of a demonic Eldritch Abomination.
The Nether is a deliberate example. Once you finish the mining tech tree and craft a diamond pickaxe, you can build an obsidian Hell Gate and enter a skyless world filled with steep cliffs, lava lakes, and giant jellyfish that spit fireballs at you while flying out of reach of your arrows. Not only will your compass spin around aimlessly, so will your watch. However, any distance traveled inside the Nether is multiplied by eight once you return to the normal world, so it can be used to travel long distances relatively quickly, once you finish digging tunnels and building bridges.
The Far Lands are an unintentional example. The entire world is procedurally generated, so the game just keeps creating more land the farther you explore. However, if you travel too far, bugs start affecting map generation, block physics, item behavior, and mob pathfinding. The game's creator has stated that although he could fix this in a future update, he doesn't intend to, since it takes over 800 hours to legitimately walk that far, and the only players likely to reach it are those specifically looking for it. He also likes the idea of the laws of physics breaking down around the "edge" of an "infinite" map. For bonus points, the Nether has its own Far Lands. As of Beta 1.8, the large changes to the terrain generator made the Far Lands not generate anymore. Some were saddened by the loss of such a unique bug. Others breathed a sigh of relief.
The latest update added an area called "The End," only accessible through portals found in fortresses deep underground. It's a barren island floating in void, it's swarming with Endermen, the sky is perpetually dark, and a black dragon flies among a group of obsidian pillars.
The Breach starts off on an ordinary spaceship, but towards the end things start to shift into a mountainous region filled with yellow mist and glowing glyphs.
Mass Effect 2 has the derelict Reaper, which can still indoctrinate despite being dead for 37 million years, and the Collector Base, an immense space station located in the accretion disc at the heart of the galaxy, which serves as The Very Definitely Final Dungeon.
The Legend of Spyro has Convexity, a gateway between the main world and the Dark Realms, occupied by the Dark Master. It's the location of the final boss battle, featuring floating platforms and strange whale-like creatures with tentacles.
El Shaddai: Ascension of the Metatron has the Tower, where the majority of the game takes place. Each floor of the tower is ruled by a fallen angel and is essentially its own pocket universe where that angel and its followers live. Locations range from a burned-out wasteland to a cutesy cartoon-like world of colorful blocks and balloons to a futuristic Tron-like cityscape (complete with cycle combat!) to an underwater world. There's also the Darkness, a location that corrupts everything that falls into it and is where the souls of the angels' followers end up instead of Heaven.
The Neath. It is very difficult to die because it's downstream of Hell. Finding one's way around it can be literally maddening.
STALKER is set in the Zone of Exclusion surrounding the Chernobyl Nuclear Power Plant after its infamous meltdown. Referred to simply as "the Zone", said location has become a place when only the most heavily-armed and foolhardy ever set foot due to both massive amounts of leftover nuclear radiation and incredibly weird shit. You've got your standard mutants, bandits and unfriendly soldiers, but the Zone in STALKER doesn't need any of those things to kill you in unimaginably horrible ways. Gravity, temperature, the causticity of your surroundings, the noxiousness of flora, physics, time and space aren't exactly constants in the Zone, and if you're caught improperly sheltered during a blowout, you'll find it's even more bizarre and even more dangerous than ever. Briefly.
The Netherrealm, which is home to the demonic Oni and is generally about the most depressing place you can be. Of course, it is the MK universe's equivalent of Hell.
There's also the Chaosrealm, where as the name would imply, nothing makes any sense whatsoever. The prevailing theme of the realm and all of its inhabitants is that they adamantly refuse to conform to any set of rules (especially the laws of physics). It is even implied at one point in Deception's Konquest mode that natives of other realms who stay there long enough will inevitably be driven insane as their mind struggles to make sense of the place.
The Boundary can be classified as this - a nexus for all timelines, and so chock-full of nastiness and mindrape that mere entry can destroy you in some shape or form. Precisely eight beings are known to have traveled through the Boundary, either for Time Travel or some other reason.
Ragna the Bloodedge: Involuntarily dumped into the Cauldron at Kagutsuchi via Nu. Becomes Bloodedge, forfeits Azure Grimoire and memories in the process, emerges 100 years in the past.
Nu: Tosses self into the Cauldron at Kagutsuchi with Ragna after conjoined impalement via Legacy Edge. Becomes the Black Beast by merging with Ragna's Azure Grimoire, emerges 100 years in the past to wreak havoc upon the world.
Lotte Carmine: Willfully entered the Boundary For Science!. Loses mind and body within moments, becomes Arakune.
Litchi Faye-Ling: Momentarily enters the Boundary to gain knowledge to save Lotte above. Gains telekinesis and ability to tap into the power from there, but is slowly developing memory loss symptoms and is in danger of turning into another Arakune.
Hakumen/Jin Kisaragi: Jumps into the Cauldron after Ragna and Nu. Goes back 100 years in time, succumbs to injuries sustained prior to dive, but otherwise emerges unharmed - all mental damages relate to transfer to Susano'o. Also engages Yuki Terumi in a duel as a diversion so Jubei and Claudius Alucard can banish Terumi to the Boundary. Emerges 90 years later at 20% power, but is physically and mentally unharmed otherwise.
Yuki Terumi: Banished to the Boundary during engagement with Hakumen. Effects on mental state indeterminate due to continuum shift induced insanity.
Relius Clover: Enters the Cauldron for reasons unknown. Emerges 80 years later, physically unharmed; memories are jumbled during transfer, but are quickly reset to pre-jump state.
Makoto Nanaya: Loses consciousness in proximity to Cauldron at Ibukido due to Prime Field Device activity, emerges in Wheel of Fortune timeline. Travels back to Continuum Shift timeline with aid of Rachel Alucard. Zero physical and mental degradation in both transfers.
Historia in Radiant Historia, as well as Granorg's Royal Hall. Its final boss Apocrypha also looks something like this, albeit shrunk.
The universe. The planets are not actually planets but the planes of the gods appearing as such due to mortals being unable to comprehend it, the twin moons Masser and Secunda are the representation of Lorkhan's rotting divinity, and the nebulae are "un-stars". The stars themselves, including the sun, are actually holes in reality created when the Aedra fled Mundus.
The many planes of Oblivion would also count.
The Oblivion planes are the Planets, but each planet is also the physical form of the Daedra Prince associated with it.
Astral Chaos in the Soul Series is a timeless alternate dimension from which the Soul Swords originate, and is filled with lost souls and an Eldritch Abomination or two.
The Labyrinth of Deceit in Kid Icarus Uprising is a maze full of fake walls, holographic asteroid belts, gravity inversion switches, and disappearing paths. And even when you're not caught up in an illusion, the walls, ceilings, and floors are decorated... odd. And did we mention it's found inside a Space Rift?
Hang Castle in Sonic Heroes, but especially its interior, Mystic Mansion. In the daytime, it's a normal abandoned castle, albeit an exceptionally large one. At night, the exteriors seemingly extend endlessly in all directions, and gravity doesn't always point downwards. Once inside, rooms suddenly change topography (sometimes when Sonic and the others are in it), things pop in and out from impossible places, there seems to be a physical upside-down version of the mansion underneath the normal one, dumbwaiter tracks twist and contort while zooming off at high speeds, Eggman's robots pop up out of thin air (presumably intentionally), and what is supposed to be a well is full of weird vaguely water-like texture in all directions with a few small brick platforms suspended in it.
The Tomb Raider series has had a few of these, but two that stand out are the Atlantean Temple in the first game and Anniversary, and Tomb Raider II's Floating Islands level. In the first example, the deeper into the complex you go, the more organic the architecture gets, until the walls are made of pulsing muscles. The Floating Islands are...well, Exactly What It Says on the Tin, a series of floating islands inside of a Chinese tomb.
One of the more benevolent examples arrives in the form of Agartha, a hollow Earth filled with branching trees, giant robotic caretakers, and a lot of bees; it's actually a divine biocomputer and font of magic in the setting, though it also functions as a confusing Portal Network usable only by those touched by Agartha's bees- given that it "precipitates a messy discord" in the flesh of the uninitiated.
On the other side of the ethical spectrum, places severely impacted by The Filth begin to leak through reality, turning into starry portals to distant and lifeless space. One of the worst examples of these is "The Breach," an excavation site in Transylvania that's been converted into a massive wellspring of the Filth by the Orochi Group and the Vampire Army; for the player, it's also a doorway to the Filth-infected Gaia Engines.
The City of the Sun God. Built by Pharaoh Akhenaten as an act of devotion to the Aten, it's built on another Filth wellspring, and the results have turned into into a gathering point for just about any malevolent force in the area; the portal to Hell open in one corner of the valley doesn't help- but it's not the most eldritch thing in the area. The centerpiece of the alley is the Black Pyramid, Akehnaten's resting place: thanks to a combination of arcane magic and the Filth's reality-warping influence, massive chambers and hallways fit inside despite clearly being too large for the structure; one of these rooms is a literally bottomless pit- above which, the dormant Akhenaten slumbers.
The world of the Gaia Engines. A semi-metaphysical landscape of black-sanded beaches under a midnight sky, dotted with massive cuboid shapes of an unknown material- the Gaia Engines. These things literally keep the world running- though Freddy Beaumont implies they can be used for "other things." For good measure, there's also a prison for the monstrous things that produce the Filth kept not too far away from the engines- and it's up to you to either reinforce the prison or help the inmates escape.
In the recent update "The Vanishing of Tyler Freeborn," the Mist surrounding Solomon Island is revealed to be hiding one of these- specifically a twisted recreation of Solomon itself under a perpetual midnight sky, inhabited only by Filth-infected versions of the locals.
Star Wars The Old Republic gives us the Voss Nightmare Lands, filled with barren soil, twisted trees, mutated wildlife, and a pervasive corruption field that reduces the weak of mind (read: everyone but the player characters) into violent psychopaths or blubbering vegetables. As an added bonus, there are no less than 5 quests available to deal with Eldritch Abominations.
Web Comics
Ravenfell in Overlord of Ravenfell is a sentient fortress made of black crystal, created through mysterious means. Beneath it is a magically shifting maze full of traps and monsters.
The Furthest Ring, a Place Beyond Time which is the home of the Horrorterrors, the Green Sun (a star with the mass of two universes, which breaks several laws of physics), and the afterlife (which exists as a series of dream bubbles). Time and space behave in incomprehensible ways in the Furthest Ring, and both become less reliable the longer you stay (or the further you go). For example, when Dave and Rose try to fly out to the Green Sun, they end up arriving in the distant past.
Dream bubbles themselves may count, as within them the conventional laws of time and space don't apply, as one can warp from memory to memory, effectively traveling forward and back in time and anywhere in space. Locations can even converge in such a way that they're a mis-match of memories of the various dreamers/dead people. For example, in one there was a mixture between Jade's island, Kanaya's home, a ruin Aradia was exploring, and some other elements.
Sluggy Freelance has plenty. The alternative dimensions vary from almost identical to the "normal" one to as bizarre as you like. One example: The Never is a hellish world where spirits become solid and living creatures become even more so than usual. Other Eldritch Locations can be found without even travelling between dimensions. Each dimension is surrounded by Timeless Space, where time is only carried by objects and creatures and will eventually run out for each of them, freezing it in place. The two Tomes of Eldritch LoreBook of E-Ville and Wayang Kulit each contain or give access into a different kind of symbolic nightmarish world that builds itself around the thoughts of an entering character.
Tales of the Questor has the Unseleighe castle of Princeling Dolan in Tir Na Nogh. Simply navigating the halls can make you arf your cookies.
Web Original
Many SCPs are Eldritch Locations. Some of them also qualify as Eldritch Abominations since they are alive. There's also the "Red Sea Object", which takes people into an alternate universe where "a god-like being of unknown origin" instigated a massive holy war hundreds of years ago, with apocalyptic results, and now giant, immortal Uncanny Valley monsters roam the land, absorbing anyone who catches their attention.
Sweet Puttin' Cakes, a miniature golf course "every bit as messed up as the cartoon on which it's based." Residents of Free Country, USA find themselves inexplicably teleported there simply by desiring to play miniature golf. The first hole is the "worm"hole, the 18th hole has par infinity, and the only way to leave is to will yourself back to reality. When Strong Bad returns, he remarks that his mouth "tastes like backwards."
We could go ahead and classify the Sweet Cuppin' Cakes world (which is apparently a real location) as an Eldritch Location. Just think of the inhabitants! A Strong Bad with a keyboard head, a black-and-white-talking wheelchair, a talking worm in a hole that appears to be able to warp from place to place. There's also the fact that characters can come from nowhere and that everything appears to be able to utilize hammerspace.
Much of the whole facility, really. Especially the brig, with that growing dark pit and half of its gravity reversed.
Brian's house in Marble Hornets became this, thanks to a certain someone. It doesn't fully follow the laws of reality and is connected to a burnt-out, industrial-looking building that is laden with even more horror.
Sarah Waite's (yes, the last name is meaningful) dorm room at Whateley Academy in the Whateley Universe. It's even called the Lovecraft Room.
Nyx Crossing, a mysterious area that centers around a section of railroad track. According to the natives, "There is no distance," and there is a mysterious monster that stalks the characters.
The Fear Mythos gives us the Empty City: a possibly living city located in an alternate dimension. The city is huge, changes every time you turn a corner, and is completely devoid of all souls.
in Demon Thesis, the four main characters attend a small liberal arts college in Canada, when a manipulative entity from another dimension begins altering reality. Only afterward do the main characters learn that their school was originally founded by an occultist who knew that the location was a place where our dimension was unusually close to and could interact with other dimensions. Said occultist intended the university to inform about the dangers of this and form a line of defense against threats, but over time the school transformed into a fairly normal university and most occult/supernatural elements have been discarded.
College Saga has the Cursed Structure (which in Real Life Babson College is known as the Fountain of Flags).
The Ghost Zone in Danny Phantom which serves as an "opposite" dimension to Earth. Home to ghosts, it's a massive world where its sky is a swirl of eerie green and black. Surrounding the majority of the GZ are (usually small) floating lands—it's rare to find giant land masses since ghosts don't really need to walk—and multiple floating doors that lead to various ghostly realms, all unique, surreal, and different based on how it fits the ghostly inhabitants.
Although it's much more light-hearted than most, Wacky Land in Tiny Toon Adventures probably qualifies. The original Wacky Land, however, featured in at least one Looney Toon short and its color remake, varies from merely inexplicable to subtly menacing in its bizarreness.
The Web in ReBoot. Dark and organic looking in comparison to The Net's bright technological look.
The Real Ghostbusters made regular use of these. From the Bogeyman's home dimension to a sneak peek at the end of the world to a ghostly pirate TV station, the series enjoyed dropping the Ghostbusters in places where physics didn't work right and the architect expected the residents to be capable of phasing through walls.
It plays with this via the Everfree Forest. While home to an assortment of beastly critters — like manticores, sea serpents and cockatrices — the ponies also regard it as horrific and unnatural because everything there takes care of itself. The plants grow on their own, the animals don't need to be looked after, the weather runs without help... it's surreal! (From their point of view, anyway.)
Played straight in the season 2 premiere with Discord's hedge maze, which could be best described as Escherian shrubbery. Not really a surprise when the architect is a Reality Warping spirit of chaos. In the second episode he turns all of Ponyville into this, and drives its inhabitants insane for good measure.
Superjail is full of these, especially within Superjail itself, but the Time Court and Time Jail in "Time Police" take the cake. Considering it's a place where all living beings from all corners of the universe and time work or are tried and imprisoned, this is to be expected.
A Family Guy skit shows Peter going into the 'beyond' section of 'Bed, Bath, and Beyond' which is a black void filled with various floating formulas and the like...and the coffee mugs he was looking for.
Regular Show the park is constantly swarming with weird people, bizarre creatures, and Eldritch Abomination that appear by ripping of the very fabric of reality.
Gravity Falls is filled with bizarre people, creatures and entities. From bears with more than a dozen heads, time travelers, to walking mass of candy.
Real Life
The page quote from Zauriel, above, well describes the surface of the sun. The innards of a star, the depths of a gas giant and the vacuum of deep space all feature mechanical properties that are incomprehensibly alien in comparison to the natural laws as we know them. Small and frail is the magical bubble in which we live and thrive.
We can do better than that: Black holes! Also, Calabi-Yau space, the universe before the Big Bang, and pretty much anything beyond the universe. And the inside of an atom. Actually, the modern understanding of physics pretty much requires a lot of drugs to understand.
Some of these have since put to contest - for example, the quantum physics as we know it doesn't allow an absolute singularity to form, even though General Relativity does, which may mean that no "true" black holes exist, whereas other theories challenge the idea of the Big Bang as the start of the Universe - it has already been all but disproved in the form it's being taught in schoolbooks, but the event's exact nature still eludes the scientists, and there are multiple conflicting theories without enough evidence to pick one over the others.
The Internet. Think about it: it manages to serve as a place, the Voice of the Legion, and an intoxicant without actually existing in the physical way most things in the universe do, it has its own laws of physics (most of which are too complex for an average person to understand) and social norms, mere exposure to it alters human behavior, it's constantly growing, changing, and altering itself, and if you tried to comprehend all of it, your brain would die screaming.
Singularities in general are this in whatever system they might manifest in. Simply, a "singularity" is an instance in a system where the normal rules of the system are inapplicable.
Planets with high gravity or atmospheric pressure can make for some extremely odd locations. There is one exoplanet for example that the scientists believe to be covered in boiling hot ice due to such conditions.
The Universe itself, if you think about it hard enough. All of those things exist within it, everything makes sense if you understand it but if you don't, it makes none whatsoever; and even that which is understandable is mostly mind-boggling. And think about the fact that in the vast, deep, huge expanse, there is only one, tiny, infinitesimally small space upon which we can exist. And even on that tiny spec, there is only a small bit ('cause remember the Earth is mostly ocean and we can't go in that, barely) that we can exist in. So a tiny, tiny spot in the infinitely large Universe. Yeah, go ahead and say the Universe doesn't count. Hell, anything outside the Universe...if it exists. Since there is no evidence so far that anything exists outside the Universe, we can only assume it would be this.
The Ocean, especially way deep down in the trenches. Creatures born without what we would see as vital to living, pillars of sulfur belch toxic superheated smoke, the pressure so intense even thick steel can be crushed easily; and that's just scraping the surface of what's down there. Supposedly, there's more undiscovered species down there than there are extinct species.
Gravity hills. Technically, they're optical illusions, but to the unenlightened, they might as well be these.
An indoor version of this in the Ames Room. There is also spatial distortion where people appear to grow or shrink in size.
