Portal Door

Wait, that's not the bathroom...

"You walk through the door to utopia and disappear."

— Dr. Hardcastle, SCP-4005, SCP Foundation

This is a door that opens to a location other than the one behind it; in time, space, and even outside of it! Its ability to connect two unrelated locations automatically qualifies it as a Cool Gate, even when the materials are of mundane make and manufacture.

How can this door bend space and time like a Dali painting? It may be a technological teleportation device, a Time Machine (or both). It could also be made through magic (which usually justifies it being otherwise mundane looking), and may lead to the Magical Land, Spirit World or Dark World. Lastly, it may be some form of "naturally" occurring gateway of Eldritch origin that leads to an Another Dimension.

This is a supertrope to The Lonely Door, where the "doorway" isn't built into a wall (it still needs to be a standard-looking door, not just a portal in the air). This is a subtrope to Cool Gate, where you can find additional portals.

---

Examples:

Anime and Manga

• Bleach: Senkaimon are doors that allow travel between the living world and the Soul Society, Garganta are portals that allow travel between the living world and Hueco Mundo or between Soul Society and Hueco Mundo. Also, there is a special doorway to hell, that opens for the collection of any Hollow that is cleansed of its post-death sins only for the saved soul to have pre-death sins that now need punishment.
• Done interestingly in Blue Exorcist, where the doors are completely mundane- it's the key that is used to open it which changes the location. This is a necessary system to get around True Cross Academy due to all the anti-demon traps.

Comic Books

• Loki: Agent of Asgard ends with Loki and Verity stuck in an endless void after the Final Incursion has destroyed nearly everything. Loki considers popping in to Doom's Battleworld, or going to bother the Silver Surfer, then thinks against it and draws a door on the void. The final page is them inviting Verity to step through. It was several years later that it turned out the door led to Galactus' homeworld in the old multiverse, but Verity simply got reset back into her old life.

Fan Works

• Batman 1939: A door inside a closet in Giovanni Zatara's apartment is a portal to the House of Secrets.
• A.A. Pessimal's The Many Worlds Interpretation: After contact is established between Unseen University of Ankh-Morpork and a fellow institution called Caltech in Pasadena, a theoretical physicist called Doctor Sheldon Cooper re-opens such a portal door between the two colleges. Between them, Leonard and Howard inadvertently open other ways of passing between Pasadena and Ankh-Morpork. This causes complications for Ponder Stibbons and Vetinari may be moved to go into Sarcasm Mode. Vetinari does realise he gave the Caltech boys the keys to one of these portals, but he still isn't best pleased. Among other things a temporal paradox is created due to Sheldon's incautious over-excitement which results in multiple versions of Johanna Smith-Rhodes.
• Weird Incident Shit: The first page has "You" from Problem Sleuth break the window on their door. This transports them to Touhou Project's Gensokyo, but there's no door leading back to the office. You are stuck in a strange and colourful world.

Films — Animated

• The door leading out of Howl's Moving Castle leads to four different places depending on what color its dial is set to. Three are The Wastes, Howl's shop in Porthaven, and Howl's shop in Kingsbury. The fourth leads through time.
• This is how monsters are able to come out of children's closets and scare them in Monsters, Inc. (and, by extension, Monsters University). The monster world has a copy of every child's closet door that when given power will connect to their bedroom. The titular factory has a vault filled with millions of them, and the climax features Sully, Mike and Boo, as well as Randall, giving chase, running back and forth through multiple doors in the vault, causing them to end up in different locations around the world. When the doors don't have any power connected, those in the monster world, including the steel banishment door to the Himalayas, which Waternoose and Randall send Mike and Sully through, will open to nothing on the other end and the closet doors in the human world will just open as normal.
• In Suzume, doors in abandoned areas will sometimes become a portal to the Ever After. The Great Wyrm can reach the living world through these doors to unleash disasters, so Closers must find and lock them. Because the Ever After is not a place for the living, humans cannot enter these doors except for a single door currently located in Suzume's hometown.

Films — Live-Action

• In The Adjustment Bureau, the Adjustors use any door to travel to any other door.
• Beetlejuice. Following the instructions in a book, the ghostly protagonists use chalk to draw a door on a wall, open it and walk through it into the afterlife bureaucracy.
• From Beyond the Grave: In "The Door", the eponymous door begins to exert a strange fascination over Seaton, and he finds that when he finally opens it, a mysterious blue room lies beyond. There, he finds the notes of Sir Michael Sinclair, an evil occultist who created the door as a means to trap those who entered through it, so that Sinclair can take their souls and live forever.
• The Matrix Reloaded. The doors that can open to different locations depending on which person or key opens them.
• Likewise in Pan's Labyrinth, in which Ofelia uses a piece of magical chalk to create a door to the Pale Man's realm.
• The Return (1980) has the portal in the back of The Prospector's mine which may lead back to the alien homeworld.

Literature

• In Patricia A. McKillip's The Bell at Sealey Head, Emma keeps opening doors and finding Princess Ysabo. She never dares go in for fear that she can't come back. And one day when she opens the door to her grandmother's room, it shows the princess in a different room. She closes it, reopens it, and finds her grandmother's room.
• Clifford Simak's "The Big Front Yard": Taine's house has been transformed, with the back and sides of his house on Earth while his front door acts as a portal to a different planet, which the aliens use to trade ideas (technology) between cultures.
• In Sergey Lukyanenko's The Boy and the Darkness, each world has three such doors that link it to a parallel world. In the novel, the Sunny Kitten takes Danny through one such door to a world perpetually covered in darkness. The door promptly gets destroyed by the Flyings. Danny manages to find the other two doors, but they get destroyed as well, leaving him stranded in this world. He has a final chance to return to his own world but sacrifices it to save his friend. Finally, the Sunny Kitten explains that the doors directly to Danny's world are gone, but there are other doors leading to other parallel worlds. Thus, they may be able to find a door to Danny's world there.
• John DeChancie likes this trope; his Castle Perilous has 144,000 doors, each leading to an Alternate Universe, and they don't just wait for you to walk through—the portals wander, and actively seek out those who want to travel or get away. His Skyway series has "Tollbooths" (no doubt named as a Shout-Out to The Phantom Tollbooth) which use miles-tall columns of virtual particles to create wormholes linking a vast Road across thousands of planetary surfaces.
• In the Chaos Gods series, the Four Realms are connected by the Gates, large portals which transport people from one Realm to another.
• Two and a half examples in The Chronicles of Narnia:
  • In Prince Caspian when Aslan sends the four Pevensies home and some of the Telmarines to the deserted island their ancestors came from through a door made of 2 vertical sticks and a horizontal one on top.
  • In The Last Battle, the door to the stable, which turns out to lead to Aslan's country (ie heaven) and not the inside of a stable that the Calormens are about to set fire to.
  • Finally, the eponymous wardrobe in The Lion, the Witch, and the Wardrobe may qualify. It's a bit of an edge case, since the actual "portal" (when it's there at all) appears to be near the back of the wardrobe - rather than through the actual doorway.
• In Chronicles of the Kencyrath, within The Master's house, there are portals to all of the worlds that the Kencyrath had to abandon in their flight.
• Susan Cooper's The Dark is Rising series. Powerful Old Ones (such as Merriman Lyon) are able to summon a magical gate (which looks like a pair of doors) that allows travel through time and space.
• In Stephen King's The Dark Tower, Roland discovers a series of doors which allow him to look into other worlds, possess a specific individual on the other side when he steps through the door, and pull that person back through the door into his own world. This is how he eventually gathers his three traveling companions who follow him in the later books. The final book ends with him finding one at the top of the Tower itself, and realizing to his horror it leads right back to where his quest began, and he's been through it before.
• The door to Brimstone's shop in Daughter of Smoke and Bone. If you enter it from the outside, it leads to a nondescript laundry room. If someone inside opens the door and lets you in, it leads to the shop. If you're going from inside to outside, you can choose to come out in any of several dozen cities around the world.
• Derek Landy's Demon Road:
  • Demon Road: Dacre Shanks has a magic key that can link any door to the interior of his dollhouses. Anyone the goes through will shrink. Shanks claims he can use the key to travel from a doorway to any other doorway but only he can control where, even if someone else is using the key.
  • Desolation: Mayor Jesper has a key similar to the in Dacre Shanks had that links any door to the cavern where Naberius is trapped.
• Dirk Gently's Holistic Detective Agency:
  • Professor Chronitis's time-traveling study in appears as a door in a convenient wall, or cliff face.
  • Reg's time machine uses the door to his bathroom to move from one timframe to another.
• "The Door in the Wall" in H. G. Wells' short story of the same name, which leads from a dismal West Kensington street in London to an enchanted garden.
• In Rebecca Lickiss's Eccentric Circles, Grandma Dickerson's house leads to a Magical Land.
• The aptly-named Gate, which was opened by a goddess of a Low Fantasy world, straight into the heart of Ginza, Tokyo.
• In Harry Potter and the Order of the Phoenix during the battle in the Department of Mysteries, Sirius Black gets pulled into an ominous veiled archway after being cursed by Bellatrix. And he hasn't been back since...
• The appropriately-named Gates in Mercedes Lackey's Heralds of Valdemar series. They have a number of important limitations, in that they are single-use constructions created by a powerful mage using his own life force, and can only go somewhere said mage has been to and knows well. The ancient Adepts of the Mage Wars, as well as the mysterious Eastern Empire, on the other hand, knew/know the secrets of Permanent Gates, which once created are simple to activate and use.
• House of Doors: The only way into the House of Doors is through one of its Doors, which function as portals, but only for those who are allowed.
• The door leading out of the title castle in Diana Wynne Jones' Howl's Moving Castle leads to four different places depending on what color its dial is set to. Three are The Wastes, Howl's shop in Porthaven, and Howl's shop in Kingsbury. The fourth leads to another dimension - modern day Wales.
  • In the title house of the third book House of Many Ways, each door in the house could lead to another room in the house or various places across the country depending on the combination of which way you opened it from, which way you turn when walking through, and how many steps you take before stopping.
• Dan Simmons' Hyperion Cantos overcomes the problem of space travel and communication with two different systems. The space travel system is essentially portals. Some very wealthy homes consist of rooms on different planets connected by these portals.
• Deborah Dixon's Illuminated: In Fiat Lux, according to Roscoe, any door can lead anywhere if you're paying enough attention.
• Isaac Asimov's "It's Such a Beautiful Day": The Door is a device that can dial up any other Door in existence, and then allow you to step between the two places instantly. It is distinct from a normal door (which merely allows access through a wall) by the capital letters. Public Doors, like public telephones, are free-standing structures instead.
• In the last volume of Labyrinths of Echo, Max and Melifaro end up in a magical reality where all doors are this for them: stepping through any kind of portal or door (even self-constructed) transports them to another world (seemingly) at random. When they finally make it back to Echo, Max discovers all doors still continue to function like portals to random universes for him, so he has to condition himself to check every doorway he passes through for this effect.
• Tim Powers's Medusa's Web: In the house, there is a corridor lined with old doors from other buildings, set into the solid wall with no openings behind them. At one point, Scott whimsically knocks on one — and it opens, revealing the house it came from seventy years earlier.
• In the Robert Asprin Myth Adventures series, the Deveel race has mastered interdimensional travel to the point that they build their house's front door in one dimension and the rest of the house in another. In addition to the obvious benefits of being able to build a house of any size anywhere you want, it allows the Deveels to use their apparent poverty as a bargaining tactic. The customer sees you selling goods out of your "humble tent," never realizing the small door at the back opens up onto an otherworldly manor house.
• One means of getting around in the endless world of The Neverending Story is The Temple of a Thousand Doors (Der Tausend-Türen-Tempel), which contains an infinite number of five-sided rooms with three doors each. Every door different in colour, shape, material etc. To get to the place you wish to go, you only need to pass through the rooms until you find the door that reminds you strongest of the thing/place/person you're looking for. This may take some time.
• In Neil Gaiman's Neverwhere (book and show), Door and her family can open up doors anywhere. Their home is a bunch of unconnected rooms.
• Doors that open to distant locations, times, and/or realities are a dime a dozen in the Nightside series, and one minor character even operates a business where people can pay to pass through any of the hundreds of Cool Gate doorways he's stocked his shop with.
• The title tollbooth of Norman Juster's The Phantom Tollbooth allows passage between our world and the Kingdom of Wisdom, though apparently only one trip each way.
• The portable door in The Portable Door by Tom Holt. A door-shaped sheet of something that can be rolled up, but when put against a wall will open to the desired location.
• The tri-portal in Dan Abnett's Ravenor, a plain wooden door that opens through space and time. Originally, it used by special trained operators, to let the questions of those who came to them direct it; when the house was broken, Ravenor operated it to put his powerful psionic abilities into play.
• In The Redemption of Althalus by David Eddings, the protagonists live in a house with as many rooms as they like, as large as they like (they occasionally have armies on the march through the corridors) and can open doors to literally anywhere on command. One of the protagonists attempt, out of curiosity, to open a door to "nowhere"—although they avert the attempt before they succeed, the concept is enough to freak out their patron goddess something fierce.
• In Sergey Lukyanenko's Rough Draft duology, the protagonist is put in charge of a Warp Zone with several doors, each one leading to a different world. Throughout the duology, he meets several other "customs officers", whose places of residence feature doors to different worlds.
• The world of The Traitor Son Cycle has seven interdimensional gates on it. The two we've seen so far both look like large and ornate doors.
• What The Hell Did I Just Read: A Novel of Cosmic Horror: NON has a door to alternate dimensions. The first time we see it, they use it to bring John, Dave and Amy into a world that has been doomed with a planet-wide plague. The next time, a NON office-worker uses it to throw his coffee cup away. The third time, one of the Fuckroach larvae is thrown in there right before it hatches. The dimension wasn't empty, and all the humans there are retroactively turned into naked, mutilated slaves of a Draconic humanoid race.
• The redstone doorways in The Wheel of Time look like empty doorframes, but walking through one will transport you to a dimension populated by weird aliens who see the future or grant wishes.
  • The Wheel of Time has them in at least three flavors: the aforesaid redstone doorways, the Waygates built of finely carved white stone and having nice reflection visual effect, and the One Power-created Gateways for Skimming (travel via subspace) and Traveling (instant teleportation).
    • There are also Portal Stones, which are Exactly What It Says on the Tin. They link not only to other portal stones in the world, but also to Portal Stones in Parallel worlds. Very handy, if not well understood at all.
• The Bob Leman short story Window involves a scientist, Culvergast, whose experiments in Magitek accidentally creates a portal in the middle of the woods consisting of a large three-dimensional "window" that takes the space where his lab used to be (apparently erasing Culvergast from existence in the process). The other scientists and the US military to look in on a seemingly idyllic homestead setting showing a family of four and their dog. Initially, they believe the window to be impassable due to an invisible barrier, but after figuring out that it weakens for brief periods at a time, a grad student named Reeves crosses over to make contact and is immediately killed and eaten by the family, who turn out to be murderous cannibals.

Live-Action TV

• Are You Afraid of the Dark?:
  • "The Tale of the Dollmaker": In the attic, the arched door leads to a suddenly life-size perspective of the dollhouse. In the dollhouse attic, the equivalent door leads to outside the attic of the original house - however, the space around this view ripples on touch, and leads to a safe landing on the lawn.
  • "The Tale of a Door Unlocked": There are two miniature wooden doors. One opens into an impending fire hazard in the Allan house; the occurrence of said hazard, and provides instantaneous passage through one of the house's inner doors. The other leads out of the house, and into the Magic Mansion.
• Doctor Who:
  • The set design and low lighting make it hard to tell, but in "Arc of Infinity" Omega's TARDIS, once it has taken off, appears to have existed as an extra tomb doorway in the wall of a crypt.
  • "Terminus" reveals that the Doctor's TARDIS can, in emergencies, materialise as a two-dimensional door in a wall instead of a three-dimensional object.
  • "The Girl Who Waited": A hallway full of doors connects all of the rooms in this facility. The portal aspect is that the rooms can be seperated in time.
• The Good Place has had three to date:
  • The portal door between The Bad Place and Earth.
  • The portal between The Bad Place and the Judge's chambers.
  • The portal between The Bad Place and Earth that Sean builds.
• In the final season of Legends of Tomorrow, in the absence of the Waverider, the team's home base becomes an extradimensional duplicate of John Constantine's house, accessed by unlocking any door with a magic key John gives Zari. Unfortunately, opening the front door of the duplicate manor reveals that the dimension in question is Hell.
• In The Librarians 2014, Jenkins uses the few magical artifacts he has in the Annex to build a "back door", a portal that connects a broom closet door to another door anywhere in the world. However, navigation is not easy and requires the use of sympathetic magic. Jenkins claims that it's a good thing he can even hit the target city. This allows the titular characters to travel the world without spending hours flying or driving. Unfortunately, it also leaves the Annex open to anyone who might stumble on the door from the other end (such as Morgan le Fay). Also, the pilot episode showed the Library itself having multiple doors leading to other parts of the world. In fact, the elevator that led to the Library was itself a portal, since the Library doesn't exist in our dimension. Later on, Jenkins manages to come up with a single-shot portable version, although that one appears to be used more as a link to the regular "back door".
• Locke & Key (2020): The Anywhere Key allows the user to travel through one door to any other in the world, only the user must have had to have actually seen the door to travel to it.
• The Key in The Lost Room can turn any door with a tumble lock into this, which is why Karl Kreutzfeld made sure all the doors in his home were of the sliding variety (he forgets about the door in his son's fake castle and another one covered by drywall). Technically, though, each door opened by the Key leads to the titular room, at which point the holder of the Key can open the room's door to whatever location he can envision.
• The Magicians (2016):
  • "Word as Bond": Julia enchants a doorframe to make a single-use portal.
  • "The Losses of Magic": Eliot's key creates a door in the Muntjac which takes him, Fen, and Frey to parts unknown.
  • "Be the Penny": Eliot's key has the power to make any door open to any other, even across realms.
  • "Do You Like Teeth?": It turns out all the keys have the property of opening doors to other places. Poppy doesn't get the chance to follow through since Benedict manages to take the key from her.
• The Ministry of Time: Each of the doors of time leads to a different place and age.
• The Night Visions episode "A View Through the Window" (based on the short story Window) features a huge portal that appears in the middle of the Iraqi desert, allowing the US Army to look in on a seemingly idyllic Little House on the Prairie-esque homestead with a loving family. As in the short story, they turn out to be vicious, sharp-toothed cannibals, and kill and eat protagonist Ben Darnell (Bill Pullman) when he crosses over at the end.
• The ABC Sketch Comedy No Soap, Radio uses the Hotel Pelican as a Framing Device for its various skits and routines. This trope is one of the methods used, where doors would open to whatever locale was convenient for the next gag.
• In Space Sheriff Gavan, the members of the Makuu organization possess space manipulation powers even when a Makuu Space isn't active. There are multiple times in the series where Retsu walks through a door only to fall off a random derelict building or a cliff in the wilderness.
• Star Trek: The Original Series: The episode, "All Our Yesterdays" has the Atavachron, a machine that creates a portal door/wall to a time in that planet's past.
• Supernatural:
  • In "As Time Goes By", Henry's blood sigil transforms the closet in Sam and Dean's motel room to a portal through time in a flash of light.
  • In "Taxi Driver", the door painted in the Generic Graffiti, which Ajay uses to travel to Purgatory.
• Wizards vs. Aliens: With the appropriate incantations, the door that normally leads to Ursula's downstairs lavatory gives access to her magical chamber.

Music

• Daniel Amos:
  • Doppelgänger has a story in the liner notes which ends with the narrator stepping through a mysterious door that leads who-knows-where.
  • Vox Humana starts with a reference to Doppelgänger's door, with the narrator in a desolate landscape with a storm-wave bearing down on him. And those notes end with the narrator stepping through another mysterious door.
• Gorillaz: The new Kong Studios apparently has various doors that allow teleportation to any given location in the world.
• TXT: In "Run Away," the boys escape to the other reality using a trapdoor on the bottom of the pool.

Podcasts

• The No Sleep Podcast: The many doors painted into the walls, ceilings, and floors in "The House of Painted Doors" lead to a dark...place where children are.
• SAYER: "30 — Doors": Several of Halcyon's doors become these unexpectedly, leading to other rooms, floors, or even dimensions that they are supposed to.

Tabletop Games

• The Lords of Gossamer and Shadow RPG is even more focused on this trope than Sigil. All the Doors in the game are actual doors, connected to an endless staircase called the Grand Stair.
• Planescape: In Sigil, the City of Doors, you can find portals that lead anywhere, literally, if you know where to look. However, not all "bounded spaces" are made from doors, so the supertrope Cool Gate may apply instead.
• A Pyramid magazine detailing spells for d20 Modern, many of which were modernised versions of classic D&D spells, had John Q's Hole in the Wall, a version of Leomund's Secure Shelter which, instead of creating a freestanding building, enchanted a door to lead into an extradimensional apartment.

Video Games

• AI: The Somnium Files:
  • Some of the warehouse doors in So's Somnium are actually portals that warp Aiba to other parts of the map.
  • The central mechanic of Saito in Boss's body's Somnium is navigating the factory using a complex chain of doors that teleport you to different places.
• Adventure Escape: There's a chapter in Midnight Carnival where a door goes to different locations based on the pattern and color of the buttons are pressed. The buttons are missing and have to be tracked down, in order to reach the final location. In universe, the portal door is probably accomplished by illusions rather than by wormholes.
• The Big Fun in Furbyland minigame In the Clouds features floating, gem-encrusted doors that will teleport the flying Furby into a pocket dimension filled with gems and jewels.
• BIT.TRIP Presents... Runner2: Future Legend of Rhythm Alien: In a cutscene, a door labeled "Broom Closet" takes the Commander to The BIT.TRIP.
• Ganbare Neo Poke-Kun: The door to Neo Poke's room apparently leads to everywhere in the universe.
• Guacamelee!: Some secret doors to Chac Mool can be found in the dungeons, also indicated with their unique icon from the map.
• Judgment Rites: A door appears at the end of "Though This Be Madness", and takes you to the next mission. It's unclear whether it's actually a portal, or whether the whole thing is nothing more than a holographic illusion.
• The Longest Journey Saga: The Shift is a single-use variant. April (and later Saga) opens it, steps through it, then it closes. There is one scene in Chapters where Saga keeps one open while other characters talk and even walk through it.
• Manifold Garden has these as the way to travel between different levels.
• A story in Mavis Beacon Teaches Typing has a time warp in one of the closets, which opens up to a random point in time and historical figures. They lock the door and forget about it - but when they go on vacation years later, the house sitter gets curious and picks the lock to the door - getting grabbed by King Richard III, who shouts "Infidel", and pulled in.
• Mystery of Mortlake Mansion has several small doors hidden all over the real-world mansion, each requiring a specifically-coloured crystal to unlock. Once unlocked, a colour/sequence/shape-matching puzzle must be completed in order to open a Swirly Energy Thingy leading to the "shadowy" version of the room in which the door is found. The shadowy mansion in Mystery of Mortlake Mansion has the same rooms as the real-world one, but connected differently (and illogically), resulting in several isolated groups of rooms which are not accessible from each other. Travelling from one group of rooms to another can only be done by returning to the real world and using another Portal Door.
• Nexus Clash: The door of a fast-food men's bathroom has been overwritten with an unholy gate to the pits of Fire and Brimstone Hell. It's implied that this may be an improvement on its previous destination.
• Persona 3 FES during "The Answer" there is a door in the dorm which opens to what ever they truly need/desire at that time. so for most of the game it opens to the mall because they needed supplies but later in the game they use it to travel to the moment when the Silent Protagonist makes his Heroic Sacrifice so that they can understand it and hopefully come to terms with it.
• Psychonauts: The Psycho-Portal is literally a tiny door that makes it possible for a psychic to enter another's mind.
• Puzzle Clubhouse: Some of the adjacent rooms in Puzzle Clubhouse are obviously not physically adjacent in space.
• Shadow Gambit: The Cursed Crew: When on land, the crew always leaves the island through a doorway to the Below. These doorways can only be seen by the Cursed, and they allow the crew to reach another portal door on their Ghost Ship, the Red Marley.
• Theta vs Pi 8: Doors in the game function like this, transporting you somewhere else in the level.
• The Vanishing of Ethan Carter has a puzzle where you enter a house, and a portal appears on each door which leads you to a room in another house. There, each door is substituted by a similar portal, where you can change the destination. Your task is to reconstruct the correct layout.

Webcomics

• Arthur, King of Time and Space: Merlin's time machine appears as a heavy wooden door in the nearest available wall.
  Mordred: Sire, the other side of that wall is the exterior hull of the ship and open space. Where did that door lead to?
  Arthur: Everywhere.
• Avania: The forces of Demonus make use of a large portal to travel between worlds. The entrance to the Chief Minister's office also appears to be some form of portal.
• Awful Hospital:
  • The "out of order" door that leads to The Abyss.
  • The Hospital and Morgue use these to access Zones that are generated from a being's "endosphere", like when Dr. Phage diagnoses a patient by traveling "inside" it and when Fern enters the Corpse World of one of her own dead bodies.
• Blood is Mine: The entrance to Zone Fifty bunkers, powered and operated by Sufficiently Advanced Technology.
• In Dream Catcher due to running in between the two worlds, Riza gets plenty of use out of a couple. One being a door, the other being the dreamcatcher.
• In the comic Flipside, creating a portal involves slapping a door-sized piece of enchanted paper on a surface.
• In Homestuck these windows return and work the same way they do in Problem Sleuth. The only difference is that the path from one window to another involves a shortcut through the Furthest Ring.
• Kukuburi: The picket gate that lets Nadia into Inbetween. Also, some hats.
• In No Rest for the Wicked, it's surrounded by Creepy Crows, it has to be dug up, it's an ordinary door—flat in the ground; and when they open it, it draws November and Clare in.
• Problem Sleuth of MS Paint Adventures features portal windows. They are treated like ordinary office appliances and must be plugged into an electrical outlet to function; if they lose power, anything midway through gets Portal Cut.

Web Original

• Deeper Up the Tower: The Tower seems to be full of these that take people from floor to floor, with yellow doors in particular being associated with Florian.
• Glowfic: Milliways sometimes "possesses" doors, turning them into portals leading to the bar. And when opened from inside the bar, its door will typically serve as a portal to the homeworld of whoever opened it, although it can be forced to open to somewhere else given the right magic.
• Haven City: Characters end up in a new City of Adventure after opening a mysterious door.
• Mahou MUSH: The Shitennou palaces are connected to the real world via such doorways. The most frequently-used is the door into Jadeite's palace, which is at the bottom of the stairs leading down to the basement of an abandoned house in Tokyo. Zoisite's palace connects to a cavern reached via the Paris catacombs; the door to Nephrite's is on the west coast of Canada, and it's speculated that Kunzite's probably opens somewhere into the Middle East (though no one has been in a hurry to test it).
• The SCP Foundation has several.
  • SCP-004 ("The 12 Rusty Keys and the Door"). SCP-004 is a door and set of twelve keys. The door opens to a different place depending on the key used to unlock it. One key leads to a room of seemingly infinite size, one leads to an Eldritch Abomination which destroys the mind of anyone who sees it, while the other ten lead to Alien Geometries which are instantly fatal to human life.
  • SCP-167 ("Infinite Labyrinth"). SCP-167 is a white cube with a door on one side. When the door is entered, the interior room has two doors. When either one of them is passed through, it leads to another room with two doors. This can be continued as long as desired. The rooms that the doors lead to remain consistent between explorations.
  • SCP-249 ("The Random Door"), which connects to a different random nearby door every time it's used.
  • SCP-432 ("Cabinet Maze"). SCP-432 is a steel storage cabinet. When its door is opened it leads to a large underground labyrinth of steel-lined corridors.
  • SCP-616 ("The Vessel and the Gate"). Once every month the center-left emergency door of a jetliner opens and becomes a portal to Hell, allowing demonic creatures to enter the Foundation's universe.
  • SCP-1130 ("A Handy Shortcut"). SCP-1130-1 is a severely weathered metal door that appears when someone uses an interactive kiosk that provides free directions. The person using the kiosk is told to go through "'Maintenance Portal 26-Sigma". When they do, they end up in a confusing maze of rooms designated SCP-1130-2.
  • SCP-1557 ("Giraffe Hell"). SCP-1557 can only be reached by passing through a free-standing door in Greenland. The door is 2.5 meters wide and 3 meters high, and has a surface temperature of over 2700 °C.
  • SCP-2317 ("Door to Another World"). SCP-2317 is an inconspicuous wooden door that transports people who enter it into SCP-2317-Prime, a dimension that holds an Eldritch Abomination.
  • SCP-2400 ("Temporal Dilation Facility"). SCP-2400 is a steel door set in a fragment of a concrete wall. When opened it leads to an apparently infinite plane of existence with ground similar to concrete and a star similar to the Sun overhead.
  • SCP-2503 ("Estimated Distance: 9,216 Years"). The door of the master bedroom of a house in Canada leads to a Bigger on the Inside alternate reality consisting of a concrete path under a dark sky.
  • SCP-4005 ("The Holy and Heavenly City of Fabled China"). People infected by a powerful cognitohazard become compelled to go on a pilgrimage to the supposed True China, which often leads to them entering some door, never to be seen again.
• Suzy's Strange Saga: The door to the Gray Building is this, and it leads to different worlds—not always the same ones.
• The Switch OCT: Ravin can create these from any existing doorway. They lead to the Hedge.

Western Animation

• Craig of the Creek's "Doorway to Helen": Two doorways are set up to create a passage to Helen's "other dimension", but they weren't actually doing anything.
• The "Doors" series of animations (1 2 3 4) features a long series of these as a framing device for a collaborative animation, wherein the black protagonist must overcome whatever each particular animator chooses to be their obstacle to reach the door to the next stretch of his journey. Ranging from elaborate fight sequences, strange spatial effects, others in need of aid, the avoidance of dragons, awkward social interactions, to even his own past self, each segment lasts from a few seconds to no more than two minutes.
• Kaeloo: Smileyland, the show's primary setting, is full of doors, and some of them lead to other dimensions.
  • "Let's Play Paranormal Stuff": Kaeloo, Stumpy, and Mr. Cat find a door that leads to the inside of Quack Quack's head.
  • "Let's Play Interdimensional Hide and Seek": The four characters use the doors to play hide-and-seek, discovering an Alternate Universe, the world of "Let's Learn" as opposed to their "Let's Play".
  • "Let's Play the Door": Stumpy finds a door that leads to the inside of Mr. Cat's head.
  • "Let's Play Replicating": Stumpy tricks his clones through a door into another dimension by telling them that Ursula is on the other side.
• Miraculous Ladybug: The superhero Dean Gate/Doorman from the "Miraculous New York" special has the power to turn any door into a portal that leads to other doors, no matter the location.
• The Owl House:
  • A major plot element in the series is Eda's portal door, which is the only known reliable method of freely passing between the human and demon realms.
  • The Secret Room of Shortcuts is full of magic doors that lead to other rooms in Hexside, which the detention kids use to peek on other classes and learn other types of magic. The doors don't need to open to other doors, instead creating doors out of whatever happens to be at the location (walls, lockers, etc.).
• The Simpsons: In a Treehouse of Horror episode, Homer finds a portal to the "third dimension" behind the bookcase.
  That's weird, it's like something out of that twilighty show about that zone.
• The title character of Mot has the power to turn any door into a Portal Door that leads to any other door he chooses.
• The entrance to the Crystal Temple in Steven Universe is a normally-featureless door that is magically augmented by the Gems to open up to specific areas depending on which Gem activates it.

---