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Beneath the Earth

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That first step's a doozy.

"All the roots hang down, swing from town to town
They are marching around down under your boots
all the trucks unload beyond the gopher holes
There's a world going on underground."
Tom Waits, "Underground" — Swordfishtrombones

A very short distance beneath our feet, there dwell fantastic beings, societies and terrors.

Those who live Beneath the Earth are often exiles from the World Above. They fled either to create a new home for themselves, or to harbor their grudge for revenge (depending on how well they did). Alternately, they may have fled to escape The End Of Their World As They Knew It. If they had better technology or more resources, they might have built an Elaborate Underground Base or even an Underground City; but if they don't they have to make do with simple caves and tunnels.

The urban area version of this trope is a remarkably livable sewer system. Sewers are surprisingly clean and warm, relatively speaking, with good lighting and electricity access. Maintenance crews never stumble across the living quarters, nor do power companies realize the drain. (Sewer Dwellers don't pay electricity bills.) New York has an especially crowded sewer system.


Go a few kilometers deeper, and the Earth's crust is filled with spacious caverns. The really lucky underground dwellers will have a Lost World thing going, with tropical flora and fauna in abundance (although occasionally with monsters like dinosaurs).

Not so lucky ones (who often want revenge on whoever forced them to live here) get gloom, fungus (often of incredible size and possibly sentient) and lava (which tends to be somehow survivable). Often based on The Morlocks in H. G. Wells' book The Time Machine. Particularly well-to-do ones will build an Underground City instead.

Often found side-by-side in with the Underground Level and Absurdly Spacious Sewer. In mythology, folklore, and fantasy, this is typically where you'll find The Underworld. (Or that other place.) In Science Fiction and pulp settings, this will often be home to the Mole Men, as well as dinosaurs in any eventual lost worlds. In fantasy, expect instead to find dwarves, goblins and dark elves making their homes down here. The King in the Mountain can also be found here, resting until his hour of need comes again. When there's a whole hidden social system living underground, in secret but fairly regular contact with the mundane surface population, that's a Wainscot Society. See also Mouse World, which is basically this but on a smaller scale, and Dug Too Deep.



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    Anime and Manga 
  • Getter Robo: The Dinosaur Empire, where evolved dinosaurs were forced to hide underground since Earth was being bathed by a type of cosmic radiation — the Getter rays — that was killing them.
  • Sgt. Frog gives us "Side 6", and underground city which functions as home and refuge for all alien immigrants on Earth. Apart from being underground, it looks exactly like any other street in Tokyo, with Expies of known locations like Akihabara.
  • Kotetsu Jeeg: The Yamatai Kingdom were a subterranean civilization, too. They had attempted conquering Japan in ancients times but they were defeated and fled underground. Big Bad Queen Himika definitely harbored a grudge and longed for revenge.
  • Mazinger Z and Great Mazinger: Not surprisingly, Mazinger Z was the one introduced this trope in Humongous Mecha anime. The Mykene were a civilization lived and thrived in the Greek island of Bardos millennia ago, using mechanical giants blast fire from their chests to protecting their land from invaders. An earthquake destroyed their island and forced them to seek shelter underground. They lived below Earth for millennia, building their cities in networks of subterranean tunnels and caverns and grafting their bodies into Humongous Mecha to survive. Unlike fromn other examples from this trope they did not strictly harbored a grudge against humans... but they did not like them, nonetheless.
  • In Tengen Toppa Gurren Lagann, all of humanity has been forced to live underground by the Spiral King Lordgenome. The inhabitants of Jiha village, at least, have been down there so long they no longer believe the surface exists.
  • The city of Lux in Texhnolyze is underground. The ancestors of the inhabitants had been banished there.
  • In Uzumaki, there is an Underground City located beneath the town of Kurozu-cho that seems to be the source of the spiral curse.
  • Made In Abyss has, well, the Abyss. Despite the name, it is for the most part well illuminated because of the fluorescent mists that pervade it. The farther down someone travels, the more elaborate its contents become, with upside-down forests, enormous plants, flying serpents, and buried cities existing in the depths. People risk death to retrieve the incredibly valuable artifacts found on the lower Layers, although past a certain point, the Maybe Magic, Maybe Mundane Curse of the Abyss means that return becomes fatal.
  • In The Mysterious Cities of Gold, the Morlock-like Olmecs dwell in underground cities.

    Comic Books 
  • There was a group called "The Morlocks" in X-Men who lived in the sewers. They were mutants who couldn't pass for normal humans. Originally the Morlocks chose to have their physical appearance altered by Masque as a sign that they had rejected the surface world. Their name is a Shout-Out to the subterranean race from H. G. Wells's The Time Machine.
    • Much deeper than the Morlocks lies Subterrannea, inhabited by yellow-skinned, weak-willed humanoids and ruled by various humans who've gone there over the centuries — most notably the Mole Man, a Fantastic Four villain. Also from Marvel is the Lava Men from The Avengers. Also lots of giant monsters (because hey, giant monsters gotta live someplace). Supposedly, most of these beings were genetically engineered ages ago by the Deviants, another subterranean race who were themselves genetically engineered by Celestials.
  • The CSI: NY comic "Bloody Murder" brings Mac and company into contact with a group of sewer dwellers under New York City.
  • Judge Dredd: Mega-City One was built right on top of the old cities of the eastern United States, which have since become the Undercity, an inhospitable area now housing feral mutants and various other nasties. It's so dangerous that it's sometimes chosen as an alternative to exile in the Cursed Earth by Judges who take the Long Walk.
  • In the Mickey Mouse Comic Universe, Wing Ding hails from Concavia, a land 5000 miles below the surface. The capital is given the name Procrasta, but if Wing Ding's people have a name, that one is not give. They are at war with the twitz, a 2-dimensional species which can turn invisible by walking sideways. A notable manner of wildlife are smoke-tigers. No explanation is given how anyone got there, which isn't surprising if one considers that "A Fatal Occupation" is inspired by Journey to the Center of the Earth, which also explained nothing.
  • The Justice Society of America comics have the realm of the Diamond Men, who break out and invade Civic City.
  • In Action Comics #272, Supergirl visits an alien planet called Terra and discovers its center was inhabited by a humanoid civilization.
  • Strata from the Power Girl comics. Their civilization is even more technologically advanced than Krypton's.
  • The League of Extraordinary Gentlemen: Several places in the League's world are this, such as the Vril-ya kingdom, Coal City, and Grande Euscare.


    Film — Live-Action 
  • The sewer-dwelling hoboes in the movie C.H.U.D. mutated into the titular Cannibalistic Humanoid Underground Dwellers.
  • In Demolition Man, the anarchist/rebel types led by Dennis Leary's character live in tunnels beneath the city of San Angeles.
  • All the way back to Metropolis. The rich live in a bright shiny modern city and the workers live in dreary underground apartments accessed by huge elevators crammed full of people at the end of each shift.
  • Star Wars Legends:
    • There are Coruscant and Taris, and any other city-planets or very large cities that get mentioned. The rich live at the tops of skyscrapers, the poor live much lower down in those skyscrapers, in slums crushed under the weight of and with the sun blocked out by said skyscrapers. And then there are the outcasts, who live either in caves, sub-basements, or the Absurdly Spacious Sewer systems required by such large populations. Star Wars is much more of a crapsack 'verse than the movies show.
    • The lower levels of the giant forests of Kashyyyk, referred to as a 'layered deathtrap' with 7 levels. The Wookies only live at the top level, with level 4 or lower very seldomly ventured to.
  • Marebito: A man obsessed with fear finds his way into a warped underground labyrinth world and rescues a feral girl who turns out to be a vampire.
  • The Matrix: Zion, Humanity's last civilization free of the Matrix is located underground, powered by geothermal energy.
  • Beneath the Planet of the Apes had one that combined urban and caverns. The humans who escaped the fall of civilization thousands of years earlier retreated to buried New York City and due to living next to a giant nuclear warhead,they became mutant, telepathic humans by the time Taylor and the rest arrived.
  • An American Tail:
    • The cat gang.
    • The exiled tribe of Native American mice in the third film (though this also crosses over with caverns, being that there is a system of small mouse-sized caves beneath the New York subway system in which the tribe dwells).

  • The Dresden Files has Undertown, an area under Chicago full of mildly-radioactive supernatural beasties, and the endless Eldritch Abomination prison extending under Demonreach.
  • Neverwhere by Neil Gaiman (based on the Live-Action TV miniseries written by him, see below).
  • The plot of the book The Relic centers around a monster living in the tunnels beneath a museum, and its sequel Reliquary had mutants dwelling in the deepest parts of New York's sewers.
  • In Neal Shusterman's book Downsiders, there is a whole community of people who live under New York City in what is really a large extension of the subway system, built in secret.
  • Suggested in the novel The War of the Worlds, as the artilleryman briefly involves the hero in a plan to form an underground resistance movement against the Martians based in the London sewers (which, he says, would be swept clean by the rain once they've fallen into disuse), using tunnels connected to cellars throughout the city. Nothing, besides a single half-dug trench, actually comes of his plan. To be fair, he'd only had a week to dig, and one can't always work.
  • Interesting example in The Chronicles of Narnia, where there is a "Deep Realm" beneath the surface of the (flat) earth ruled by the Lady of the Green Kirtle, but it turns out that many of the enchanted slaves there are actually from an even deeper realm called Bism, where gemstones are alive. Once roused from their enchantment, they find the so-called Deep Realm uncomfortably close to the sky...
  • The fairies in the Artemis Fowl series fled underground in order to hide from humans, and while not exactly thrilled to be there, they've made quite a society nonetheless.
  • Khazad-dûm, in The Lord of the Rings is beneath Middle-Earth.
  • The Tunnels series takes place almost entirely underground. Starting with the discovery of an underground city called the Colony, the protagonists move progressively deeper with each book.
  • In the fourth book in the Oz series, Dorothy and the Wizard in Oz, Dorothy is reunited with the Wizard, and they make a journey through various realms beneath the Earth, before coming back to the surface in Oz.
  • In Mikhail Akhmanov's Ash, humanity's only extrasolar colony is nuked in The War of Earthly Aggression, resulting in survivors hiding in an underground city built just prior to the destruction. Other survivors live in a base under the ocean. Earth forces have no idea anyone survived but continue to nuke the surface. The underground survivors are building nukes to retaliate against the enemy base.
  • In Shadowmarch series, Funderlings designed and built entire town beneath the Southmarch castle, as well as labyrinth of caverns and tunnels beneath it. Similar subsurface Funderling town exist beneath Syan, and there are probably other beneath various cities through Eion.
  • The novel Dark Cities Underground posits that this trope exists as modern-day fiction's retelling of the myth of Osiris.
  • Deltora Quest: Lief, Barda and Jasmine discover the descendants of the Pirrans living on underground islands beneath Deltora.
  • The Darke Halls in Septimus Heap are a huge, subterranean cavern that forms a Darke realm.
  • In The Iron Teeth web serial, the protagonist Blacknail was born in tunnels beneath a human city. His tribe used to live there for generations. A large monster filled network of caves called the Deep has also been mentioned, but only briefly explored. Small insects called Harvesters live there and build vast mushroom farms.
  • The Underland Chronicles is all about this trope. More than 90 percent of the books take place in an underground world beneath New York called the Underland.
  • The Weirdstone of Brisingamen's svart-alfar live beneath the earth, and the protagonists have to spend some time spelunking through abandoned (human) mine workings as well.
  • In Whispers Under Ground, Peter Grant discovers an underground colony hidden amongst the Tube networks, the sewers and the illegal teenage raves of London.
  • In E. M. Forster's story "The Machine Stops", humanity lives in underground complexes, as the surface air is cold and poisonous. Or at least that's the official story.
  • Common wartime workers in Philip K. Dick's The Penultimate Truth live and work in underground "ant tanks" while armed robots fight on a fatally irradiated surface. One of them, Nicholas St. James, is sent to the surface and learns that the war has been over for years and its engineers have kept them below surface in order to take the land for themselves.
  • Roland Smith's Beneath sees the protagonists winding up in a colony of people under New York City... whose leader is plotting to one day return to the surface and take over.
  • In Below, nobody knows who built the Elder Kingdom: a sprawling underground network of cities, mines, and tunnels between them. It was abandoned so long ago that the Romans found it empty of people when they explored, and now only dangerous creatures live there.

    Live-Action TV 
  • The 100: The Mountain Men live in an enormous underground bunker inside Mount Weather, as the radiation levels on the surface are lethal for them.
  • Angel has Angel and company stumbling onto a community of sewer-dwelling kids after Jasmine takes over the outside world. Not to mention the Buffyverse has all the demons, vampires, ect, that live down there.
  • Beauty and the Beast featured "the World Below", an elaborately gothic underground colony secretly constructed long ago and connected with the sewers and subways of New York.
  • In the Bones episode, "The Woman in the Tunnel", Brennan and Booth investigate the murder of a woman who was doing a documentary about an underground society under Washington D.C. Brennan finds the society fascinating.
    Dr. Brennan: Every society has its bottom-dwellers, and every society fears its bottom-dwellers, because they are a symbol of what happens in that society if you fail.
  • The Compass Killer on CSI: NY was tracked to his hiding place in a forgotten underground apartment beneath a park in Queens, and pursued through adjoining storm drains and sewer tunnels.
  • Doctor Who:
  • The miniseries and novel Neverwhere (both by Neil Gaiman) mainly take place in an elaborate underground society beneath the streets of London. There's definite magic in the setting, though, and some hints that the lower chunks of the system aren't really connected to the "real" world.

    Tabletop Games 
  • Shadowrun:
    • The Seattle Underground, a real-world complex of abandoned and buried buildings from the 19th century, has been colonized by orks and trolls as a cross between this trope and an ethnic neighborhood.
    • Thousands of years earlier in the same Verse, artificial underground cities called kaers provided shelter for Earthdawn's inhabitants during the time of the Horrors.
  • Several Old World of Darkness games incorporate this trope. Vampire: The Masquerade has Nosferatu warrens, while Werewolf: The Apocalypse has Black Spiral Dancer hives.
  • Underworld, a relatively obscure RPG, has a setting and flavor similar to that of Neverwhere, but set under New York City instead of London.
  • Pathfinder: The crusader city of Kenabres is built over a system of Absurdly Spacious Sewers, catacombs, tunnels and bunkers built over and out of a preexisting cave network. The Kenabres catacombs were built in haste and are poorly mapped, and have over time become home to pariahs, criminals and a large population of mongrelmen — Beast Men with the features of several animals at once — descended from people mutated by the influence of the demons of the Worldwound that Kenabres' crusaders struggle to hold back.

    Video Games 
  • City of Heroes:
    • The titular city has an impressively large, intricate, cavernous, and heavily-populated sewer system. If heading down there, expect zombies, evil cultists, devil-worshippers, Nazis (untill they got RetConned out, anyway) and cyborgs. If you head deeper into the Abandoned Sewer System, you'd better bring friends, since it's virtually covered with interdimensional mutants, hostile aliens, demons, ghosts, and the occasional tentacled superdimensional monster-of-the-week.
    • The "lost city of Oranbega", archaic and arcane ruins teeming with the Circle of Thorns and their summoned behemoths which lies beneath even the sewers.
  • Metro2033 features the post-apocalyptic variant, with a small civilization of humans clashing in the depths of the Moscow underground railway after a devastating global nuclear war.
  • In Final Fantasy XII, after The Empire invades Rabanastre, all of the city's inhabitants are forced to live in the underground tunnels formerly used for storage of goods and merchandise except for the extremely wealthy people.
  • The Locust Horde in Gears of War lives underground. The day that they began their war against humanity is referred to as "Emergence Day" due to them bursting up out of the ground.
  • The Myst series includes the D'ni Cavern, 3 miles below New Mexico and filled with a lake of glowing algae that acts as sunlight.
  • Fallen London takes place in a version of Victorian London that was transported under the earth as part of three terms of a Deal with the Devil on the part of Queen Victoria to save Prince Albert's life. Its spinoff, Sunless Sea, explores the Unterzee, the vast underground ocean that surrounds London.
  • Rock Bottom and the Mermalair from Spongebob Squarepants Battle For Bikini Bottom.
  • The subterranean world Derek Badger of Poacher finds himself trapped in does not only have towering cities inhabited by disembodied spirits, but also beaches and forests, and even a jungle.
  • Project Eden takes place almost entirely under a futuristic megacity. It's not all sewers, either — a lot of the game area once was inhabited, or part of massive maintenance systems and factories. Some neutral characters still live down there... along with a lot of hostile ones.
  • Subterranean Animism, the eleventh Touhou game, gave us the underground city Former Hell. It's the place where Hell used to be, but now it serves as the city where Youkai who are hated by other Youkais because of their dangerous abilities live.
  • The Tunnelers in Fallout: New Vegas: Lonesome Road resulted from the mutation of the Divide's residents who took shelter underground during the Great War. The second nuclear catastrophe, triggered by the Courier, released them to the surface.
  • Most of the EarthBound ROM Hack Unearthed takes place underground, with several locations having underground villages with their own species and ecosystems. You do go to the surface on occasion, but it's often for minor things such as getting items.
  • Sheltered is mainly set in an underground bunker that the family is living in in the post-apocalyptic Earth.

  • In Sluggy Freelance, the tunnels beneath Kesandru House (or where it once stood) were originally just a squat stretch of bare earth that Bun-Bun hung out in. But then the Dig-Bots (tiny, self-replicating robots designed to improve the living space) got to work. Eventually they built their own night club down there, and their own mall.
  • Some dragon cities in the comic Dragon City are in various human cities (such as Dragon City New York). Most sewer workers in those cities know about the dragons.
  • The Girl Genius version of Paris has large sections of its population living underground.

    Web Original 
  • Night Vale's Desert Flower Bowling Alley and Arcade Fun Complex is purported to contain a vast underground city beneath the pin-retrieval area of lane five. However, expectations are confounded when it turns out the city beneath Night Vale is actually a miniature metropolis. Unfortunately, its citizens are still quite dangerous, as Carlos finds out to his peril.
  • Mahu: In "Second Chance" the fleeing people of Earth appear on a new planet covered in ice and snow. The surface makes like difficult, if not impossible for normal humans, so most of them choose to inhabit and create expanding cities underground.

    Western Animation 
  • Fruity, Matt and Chaka in MTV's Downtown venture into the subway tunnels in New York so Matt can tag the trains; while they wander around, they talk about all the crazy inhabitants they've heard tell of. Suggestions include: survivalists, mole people, giant snakes, and transit cops who stage fights.
  • Futurama took on this trope, too, with a civilization of mutants living in the sewers of New New York. However, Fridge Logic can make one wonder why they don't use the ruined buildings rather than make their own junkheaps out of things flushed down the toilet. Maybe it's the running water, or maybe the writers felt that the Rule of Funny justified the contrast. It is also rumored that there's a freakish race of sub-mutants living in the sewers of Old New York (under the sewers of New New York), but that's just a sub-urban legend.
  • An underground community of homeless people were featured in Gargoyles. The Labyrinth Clan, humans mutated into feline-gargoyle creatures, became their sworn protectors since they could not return to their old lives.
  • The Simpsons:
    • Parodied in "Hello Gutter, Hello Fadder", in which the sewers beneath Springfield contain Morlocks, C.H.U.D.s and Mole People (led by Hans Moleman).
      Moleman: There is no escape from the Fortress of the Moles!
      [Otto/Homer's bungie-cord retracts, pulling them upward]
      Moleman: Well, except that.
    • When Homer told the story of his first trip to New York, which culminated in him falling down an open manhole.
      Homer: ...and that's when the C.H.U.D.s came at me.
      Marge: Of course you'll have a bad impression of New York if you only focus on the pimps and the C.H.U.D.s.
  • The Teenage Mutant Ninja Turtles live in New York's sewer system.

    Real Life 
  • In case you thought it was all fiction, check this.
  • There were so many catacombs, caverns, tunnels and quarries dug out beneath Rome and Paris that the ground is like swiss cheese. (buildings began falling into the ground) and had to be filled in with artfully stacked rubble made of the bones of millions of plague victims. Rome's catacombs were reputedly inhabited by persecuted Christians. Easy access to limestone bedrock, which could be quarried and burned to produce mortar and fuel, is probably why these cities grew so large in ancient times. The extensive network in Rome is such that it seriously impedes construction of the city's Metro.
  • Watch Cities of the Underworld on History channel.
  • Many, many people live underground in Paris, Rome, New York, and possibly other major cities. They range from the occasional traveler (mostly the case in Paris) to the homeless (the case in New York)
    • In 2003, the French police found a 400 square meter cinema in Paris's underground, fully equiped with electricity, phone, and a small restaurant. The Parisian police even have a dedicated squad patrolling the underground to chase intruders.
  • In 1934, G. Warren Shufelt, working off of a Hopi legend of the Serpent Brothers, went in search of the lost underground city of the lizard people, tunneling a shaft down a thousand feet in downtown LA before eventually giving up.
  • The town of Coober Pedy, Australia. The only reason it exists is because opal was discovered there. Diuring the summer, surface temperatures can reach 50 Degrees centigrade, so the 2000-some residents all live in (quite luxurious) underground houses.
  • The ancient city of Petra, Jordan, carved out of rock. It was recently named one of the New 7 Wonders of the World. Most of these 'buildings' are only façades. It is thought that the carved out buildings are either tombs, temples, offices etc. Most of the daily activities were going on in the camp on the plain between the mountains.
  • As noted above in the Shadowrun entry, following an enormous fire in 1889 and having a constant battle with tidal flooding, the city of Seattle rebuilt its entire business district one story higher, on top of the mostly filled-in ruins of the first version, leaving a motley collection of privately-owned tunnels, many of which exist to this day; some of them have been cleaned out and host tours.
  • Theme parks such as Disneyland, interlinked museum networks such as the Smithsonian Institute's D.C. facilities, and major hospital or university complexes worldwide tend to have elaborate networks of tunnels, storage facilities, offices and logistics below ground level, where the guests/patients/students never see them.


    Anime and Manga 
  • The Inner World is a location in the unique anime sci-fi action anime series Spider Riders that exists deep beneth the planet Earth. There live two subterranean civilizations that live in the Inner World. There are the humans, and the Insectoid People called Insectors/Invectids.
  • Subterranean civilizations armed with giant Robeasts are perhaps the second favorite Super Robot series antagonist after Alien Invaders. One of the first examples is the Dinosaur Empire of the Getter Robo series, followed only a few months later by the Mycenae Empire in Great Mazinger.
  • In a variation, Masō Kishin Cybuster (loosely on Super Robot Wars) has a world in the middle of the Earth, though this might be a magical dimension. Naturally, this is based of the world of La Gias in the Super Robot Wars series
  • Tengen Toppa Gurren Lagann has a DIY version, with caves dug out.

    Comic Books 
  • Common in comics of yesteryear. Superman, Spider-Man, the Fantastic Four, etc. have all had to deal with angry molemen.
  • Amulet: Sort of; it's implied that Alledia is actually a sort of alternate Earth. But they definitely get there by going down a very, very long staircase.
  • Disney Ducks Comic Universe: It's revealed in the aptly titled Land Beneath the Ground that the entire Duck Earth is apparently filled with two races, the Terries and the Fermies, with the world they live in being referred to as Terry Fermy by these residents. They are the ones responsible for causing earthquakes.
  • The Transformers introduced violent "Mutants" who live deep below Cybertron's surface and make a point of hunting any Cybertronian that enters their domain.

    Comic Strips 
  • Flash Gordon has the Cavern World of Syk, home of the Blue Magic Kingdom ruled by the Witch Queen Azura. That's beneath Mongo, not Earth.
  • Prince Valiant has the subterranean realm of the Dawn People. The current storyline has Val traveling through it to rescue Aleta, encountering monsters and what-not, in something very reminiscent of an old-school D&D dungeon crawl.

  • The Palaververse: An extensive underworld exists beneath Theia’s surface, permeating the planet’s entire volume down to its core in a maze of tunnels and caverns, underground rivers and plumes of lava rising from seas of magma. The uppermost layers are (relatively) tame and home to the underholds and mines of the Diamond Dogs, but the deeper levels are home to things like sapient colonies of fungi, living patches of darkness or poisonous gas, blind and flightless cave dragons and the Dwellers Below, eldritch abominations spawned by primal and chaotic magic. Supposedly, the Diamond Dogs originally lived in the planet’s very heart, but migrated upwards to their current location after an apocalyptic “Creation War” between unspecified empires turned the planet’s core into a sea of molten rock.
  • In The Unfantastic Adventures of Bizarro No. 1, the Blue-Kryptonite Men live in a network of caverns under the surface of Bizarro World.

    Film — Animated 
  • The Incredibles parodies the tendency for comic book supervillains to come from here with the Underminer at the end of the movie.
    "I am always beneath you, but nothing is beneath me!"

    Film — Live-Action 
  • An uncharted cave in The Descent hosts a group of Gollum-like, blind, stunted little cave people with remarkable agility and bat-like sonar capabilities.
  • The underground civilization in Superman and the Mole People reveals itself when a deep well penetrates the rock around it.
  • The 1976 Doug McClure movie At The Earths Core, which is based on the Pellucidar stories of Edgar Rice Burroughs, mentioned in the literature section below.
  • The Lord of the Rings: Moria, the subterranean dwelling of the Longbeards Dwarf clan under the Misty Mountains.
  • Star Wars: In The Phantom Menace, the planet Naboo is riddled by a tangle of flooded caverns inhabited by gigantic fish and monstrous leviathans, used by the Gungans, who live in its uppermost reaches, as a swift but risky path through the planet. The humans living on the paradisiacal surface are apparently completely unaware of this, as they happily build their cities and homes along the shorelines of bodies of water that lead directly into the monster-filled abyss.

  • In More Information Than You Require, the Mole Men live here with thir hideous steeds and the Trogloditic men. Fortunately for mankind, the Mole Men are relatively nice 18th Century Enlightenment-types
  • In the 1930 short story "The Mound" written by Zealia Bishop (but ghost-written by none other than H. P. Lovecraft) a Spanish conquistador descends into an underground world of caverns bathed in blue light called K'n-yan. In true Lovecraftian fashion, this world proves only the first of a succession of otherworldly abysses. Below K'n-yan is the grotesque, red-lit world of Yoth and below that is the nightmare realm of the lightless N'Kai.
  • The Pellucidar novels of Edgar Rice Burroughs also qualify, with one big "cavern" consisting of the entire core of the Earth, complete with an internal miniature sun! Tarzan even went down for a visit in one installment.
  • In David Eddings' The Belgariad, the Ulgos have lived in the caves below Ulgoland for centuries. They are featured particularly in Magician's Gambit.
  • Haven City, home of the fairy folk in the Artemis Fowl series. Given the quantity of Phlebotinium to which the Fey have access, Haven City is really more an Elaborate Underground Base than a simple Beneath The Earth dwelling.
  • Caverna from A Face Like Glass. It is the size of a kingdom, brimming with Alien Geometries, and may or may not be alive. Where it is located is never explained further than underneath a hill either in or near a desert.
  • Underland in C. S. Lewis's The Silver Chair, the fourth (or sixth, depending whether you go chronologically or by date published) book of The Chronicles of Narnia. However, the topmost layer is all the protagonists get to visit; turns out there is a world much much further down below called the Land of Bism.
  • The Tunnels series. Although ostensibly children's novels, the series is surprisingly dark as well as surprisingly good, and is set almost entirely in a Crapsack World which lies beneath our own.
  • Jules Verne's Journey to the Center of the Earth takes place primarily in a complex network of caves beneath the surface of the Earth, accessible through volcanic vents. There’s even a subterranean ocean, the Lidenbrock Sea, which fills a single titanic cavern, is lit by constant electrical storms, and is inhabited by Prehistoric Sea Monsters.
  • Tad Williams' Memory, Sorrow and Thorn series heavily utilizes this trope. Not only is the Hayholt, capital of Erkynland, built atop the ruins of the Sithi city of Asu'a, but the entire continent of Osten Ard seems to be riddled with caverns and tunnels, the majority of which were constructed or at least "tamed" by the Dwarrows over countless eons. The Dwarrows use these tunnels to travel from one ancient city to another while remaining completely unobserved by mortals and Sithi alike. The tunnels beneath the Hayholt in particular are a major plot device — The Hero Simon gets lost there no less than three times and they are used by various factions to bypass the castle walls during the final battle. Further, they serve as a metaphor for Simon's Character Development.
  • Tailchaser's Song has Vastnir, an underground fortress and extensive tunnel complex in the far north of the world. It's a nightmarish place populated by various mutant cats and enslaved normal cats, run by fallen god Grizraz Hearteater.
  • The Descent and Deeper are novels dealing with the revelation that our entire Earth is riddled with this trope, and that cannibalistic near-human creatures inhabit the global maze of tunnels.
  • The Age of Fire series has the Lower World, a network of tunnels and cave systems said to be home to most of the surviving dragons. It is often mentioned during the first two books but only rarely and briefly explored. In contrast, most of the third takes place there; it turns out that the Lower World is not only absolutely massive, but may well be just as populous as the Upper.
  • Lovecraft lives on this trope. Pick a story, pick any story, 9 times out of 10 there's some chance that the "long-lost subterranean civilization of awkward syllables" will be mentioned.
  • The animals in Roald Dahl's Fantastic Mr. Fox build a labyrinth of caves and tunnels to live in and steal food from the rather nasty human villians.
  • The kingdom of Subterranea in the Doc Savage novel Murder Melody (although it takes the heroes about half the novel to actually get there).
  • In The Sister Verse and the Talons of Ruin, the cavernous salt mines beneath Octavia uncover the ruin of a massive labyrinth, home to any travelers unfortunate enough to wander inside, and an Eldritch Abomination that traps people in their dreams while it eats them.
  • In the Star Trek: Rihannsu series, the Romulan/Rihannsu colony world Ysail is famed for its vast Saijja Caverns, a network of caves so vast and deep that they cannot be accurately scanned from orbit and have never been mapped. When the Rihannsu government becomes more oppressive in the later books, most of the Ysailsu retreat to the deepest explored parts of the caves, which become an excellent base for La Résistance.
  • Dinotopia has the World Beneath, which was home for many years to the dinosaurs, who hid there to escape cataclysms in the outside world. Later, refugees from the sunken city of Poseidos hid there to try and restart their factories that built their robotic beast-vehicles, but they failed, abandoning the 'strutter-works' and handing over their treasure to the tyrannosaurs for safe passage through the Rainy Basin.
  • The Books of Ember: The City of Ember is a post-apocalyptic bunker the size of a city that was built inside a colossal natural cave. Leaving it or entering it involves a climb up or down steep natural tunnels and a trip down an underground river.
  • The main setting of The Uncommners is Lundinor, a city under London, England. It is one of many secret "undermarts" in the world, where people buy and sell everyday objects made magic due to being imbued with human souls.
  • Isaac Asimov's David Starr, Space Ranger: Mr. Benson correctly predicts that the Martians have moved underground where they dug a vast network of underground tunnels to retain liquid water and atmosphere. He suspected that the Martians may have been poisoning the Earthmen's crops to get rid of the invasion.
  • Lester del Rey's "The Wings of Night": Lhin and the other Lunarian ancestors moved under the lunar surface many eons ago, when the moon's atmosphere evaporated away.
  • In Kane story "Two Suns Setting" there is the strange cavern system hidden beneath dwarf king Brotemllain's burial cave. It's inhabited by huge, white, blind beasts, including a yard-long white cockroaches, as well as sabretooth tigers.

    Live-Action TV 
  • Doctor Who:
    • "The Web Planet": Ian meets pale, flightless descendants of the Menoptrans, who'd survived underground for generations since the Zarbi took over the surface of Vortis.
    • The Silurian city in "The Hungry Earth"/"Cold Blood", which lies in a cavern many miles beneath rural Wales.
  • An inversion occurs in the Farscape episode "Taking the Stone". Our heroes land on a "royal cemetery planet" where the surface is covered in the graves of deceased royalty and a society of young hippies live in underground caverns. Moya's crew discovers that the inhabitants are suffering from the effects of radiation which is amplified by the caves. Unlike most examples, the safer thing to do is return to the surface, even with all the graves...
  • All the Fraggles of Fraggle Rock lived in an elaborate cave hidden behind Doc's workshop. Or beneath the lighthouse, in the UK version. In both cases, exactly where the Gorgs' garden was in relation to the human world was completely unexplored.
  • MythQuest has Alex venture underneath the Earth and into Hades to rescue Euridice.
  • The Victorians from Ultraman Ginga S are a subterranean civilization of humans protected by Ultraman Victory and the monster Shepherdon. They dwell in massive caverns with light provided by giant Power Crystals called Victorium. However, when aliens begin to pull Victorium to the surface in a plot to resurrect the Big Bad, the Victorians come into contact with the surface world.
    • The Victorians were partially an homage to an episode of the original Ultraman that featured a highly advanced civilization of eyeless Human Subspecies that sought to conquer their surface kin by enslaving Ultraman and unleashing their own monster named Telesdon.
  • In The Young Ones episode "Boring", our heroes are all bored out of their skulls. Meanwhile, just below their house, the king of the underground kingdom where nothing boring ever happens laments the fact that he may never meet a boring person.


  • Older Than Print: In both the ancient Norse and Celtic Mythologies, certain supernatural folk lived underground or within and beneath hills and mountains.
  • We'll call it "mythology" for lack of a better term...during the late 19th Century and early 20th, a number of people became convinced that the Earth was hollow, and inside there was a lush paradise of eight-foot-tall blonde genius-poets who were, in many cases, hermaphrodites, usually supposed to be the perfect ancestors of humans. John Symmes even got some support from Congress to go look around the North Pole for an entry-hole. (John Hodgman covered this in his second book, but he wasn't as far off as you might expect.)
  • African Mythology: According to the San tribe, humans and animals lived in underground caves until the creator Cagn lead them to the surface.


    Tabletop Games 
  • Dungeons & Dragons: A subterranean world is a common fixture throughout the various settings and editions.
    • In Forgotten Realms and Greyhawk, it's called the Underdark, and both use it in more or less the same way — a very hostile environment filled with ancient evil races where Everything Is Trying to Kill You, and the traditional home of the Drow.
      • It's far from uncommon for entires cities to exist in the caverns — Forgotten Realms, for instance, has Skullport directly under the city of Waterdeep, where it serves as a trade hub between the surface world and the Underdark, and the Garden City of Fluvenilstra, built into the giant mushrooms and other magically enhanced plants that dominate the local landscape and home to a robust population of Mushroom Men.
      • In 4th edition, legend has it that it most large tunnels in it were carved out by the blind, agonized strugglings of Torog, God of Imprisonment and Torture, to escape after he was entombed alive during the Dawn War against the Primordials, smashing through the dimensional walls between the mortal world, the Feywild and the Shadowfell in his efforts.
    • In Eberron, the underworld is called Khyber after the primordial dragon-god from whose body it was purportedly created. Khyber is a world of pitch blackness, ruled by Eldritch Abominations from Xoriat, the realm of madness. Cults of surface-dwellers worship the mutagenic energies that emanate from its black crystals.
    • Ravenloft dosen't have an underworld that spans the entire setting, but one of the islands in the Mists is built on taking this trope to its most horrible conclusion — Bluetspur, home of the mind flayers. Also, the Arak shadow fey lived in a Beneath the Earth environment before the Shadow Rift appeared, while the domain of Timor relocated to lie underneath that of Paridon.
    • The Known World (later renamed Mystara) took this the whole nine yards and made the world hollow, lined with pocket societies placed there by the Immortals to preserve ancient cultures and organisms that had gone extinct on the surface. This setting was called, sensibly enough, the Hollow World. The planet's crust between the Hollow World and the surface also had the typical cavernous underworld, inhabited mainly by the shadow elves.
  • In Pathfinder, the world beneath is known as the Darklands and draws inspiration from pulp fiction of the early 1900s, such as Edgar Rice Burroughs's Pellucidar. It's divided into three layers:
    • The uppermost layer, Nar-Voth, consists of extremely deep and extensive but otherwise fairly normal caverns (which are often isolated and do not form a continuous network), and is the most familiar layer to the surface-dwellers. While most of it is sparsely populated stony wilderness, it is also home to fairly normal humanoids like goblins, troglodytes and duergar, and some less normal ones like derros, vegepygmies, and mongrelmen.
    • Sekamina, the middle layer, consists of much larger and more thoroughly interconnected caverns and tunnels, extending beneath most of the world’s surface. It is home to more reclusive and dangerous races like the drow and ghouls, who rule true underground empires, alongside monsters such as driders, morlocks and gugs. It has more exotic terrain than Nar-Voth, including fungal forests, volcanic caves and a true subterranean sea.
    • Finally, the deepest level — the Vaults of Orv — is as much a subject of fear and mystery for the people of Nar-Voth and Sekamina as the Darklands as a whole are for surface-dwellers. It consists of massive caverns the size of nations, some dark and others lit by artificial suns or glowing crystals, containing environments such as deserts, rainforests, ruined cities, mountain ranges and a vast subterranean ocean. The Vaults are inhabited by a great variety of monsters, ranging from dinosaurs, dragons, monstrous arthropods and the undead to a variety of unspeakable horrors. They did not form naturally, but were excavated by a powerful earth elemental Precursor race called the Xiomorn to host their evolutionary experiments.
    • The Darklands also extend beneath Tian Xia in the far east, although there they are home to creatures such as oni, the Denizens of Leng, haunted clockworks, Rat Men and cave giants rather than the races of the western Darklands.
  • Lamentations of the Flame Princess: The expansion Veins of the Earth features an endless labyrinth miles below the earth. Treasure is plenty down there, but food and light are worth their weight in gold.
  • Warhammer:
    • The Skaven have a vast "under-empire" centered under the ruins of Skavenblight, with tunnels stretching all over the world. The Dwarfs likewise created immense tunnel systems under much of the Old World's mountains, which in the modern day largely lie in broken ruin and are home to teeming tribes of trolls and night goblins, voracious fungus creatures and numerous dragons. Combined with preexisting natural caverns, these create immense, interconnected cavern systems stretching beneath much of the world.
    • The Underworld Sea is a vast labyrinth of flooded caves and tunnels stretching beneath the Dark Elven realm of Naggaroth. It's poorly explored, difficult to navigate, prone to floods and cave-ins and populated by ferocious monsters, and there are rumors that the ruins of a lost civilization exist within its depths. Similar abysses are suggested to exist beneath much of the world, deep beneath the diggings of Dwarfs, Skaven and Goblins, hiding enormous blind horrors, vast Blob Monsters and cities of ghoulish things where no light has ever shined.
  • Exalted: The Mountain Folk live underground in a Forever War against the Darkbroods, monstous races inhabiting even deeper tunnels far below the Flat World. This was caused by the Solar Exalted, who grew jealous of them, and forced Autochthon (their maker) to geas them into staying underground unless an Exalted said they could come up. Autochthon had the appropriate response to this, and left to Elsewhere.
  • The Underneath in MagiNation is home to a large city and fungus jungles.
  • Yu-Gi-Oh!: The Subterror archetype, in particular the Behemoths are all depicted as gigantic monsters living underneath the earth. This is emulated with their effects, which involve flipping themselves face-down and then using their abilities when they are flipped face-up.
  • Space 1889: The World Beneath the World is a complex system of caverns and tunnels running beneath the global jungles of Venus. It's formed from the constant growth of planet's vegetation burying older layers of the jungles and swamps beneath newer growth and rotting humus, forming a spongelike system of subterranean cavities supported by the petrified remains of ancient trees.
    • This underworld is home to a complex ecology supported by the constant percolation of organic materials form above, mostly consisting of oversized arthropods, tangled fungal growths and sundry bioluminescent organisms. It's also home to the Gri, eyeless, albino relatives of the Venusian Lizard Folk who have been eking out an existence in the caves for generations and have only sparse contact with their surface relatives and the human colonists.
    • The World Beneath the World does not form a single world-spanning network; most of it consists of solitary caverns and small cave systems, and although complexes as large as Australia exist these are not extremely common. However, some speculate that even deeper caves exist and connect the shallower cave systems to form a titanic underworld, chiefly due to the uniform nature of the various cave systems' fauna.

    Theme Parks 
  • The Journey to the Center of the Earth attraction at Tokyo DisneySea is based around this concept.

    • Onu-Koro and Mangaia.
      Lewa: Has anyone noticed how every time we go underground something bad happens?
    • There's also a "universe" under the island of Mata Nui. It's not technically underground, being inside of a Humongous Mecha that crashed onto the planet a thousand years ago, but from the perspective of the Matoran...

    Video Games 
  • The RTS Cave Wars. True to form, your resource-management includes ensuring a good mushroom-harvest...
  • Wherever you don't find sewers in City of Heroes, you'll find caverns, with entrances in every park and abandoned lot. The caves tend to house either trolls (former humans mutated by exposure to a drug that induces super powers), beings of living stone, or the various groups of evil magicians. Occasional inter-dimensional aliens may be spotted, usually busy redecorating the place into an Elaborate Underground Base. Lampshaded at least once in the intro text to a mission, describing your character wondering how any of the buildings in the city keep standing when the ground below is like Swiss cheese.
  • In Deadly Rooms of Death, the great underground empire is actually more advanced than the simple agricultural society above.
  • The RPG series Exile (and its remake, Avernum) takes place in a gargantuan network of underground caverns, stretching for several kilometers in every direction, and varying from huge caves big enough to have their own weather systems, to twisting little mazes of passages, all alike. As the name of the area suggests, the people who live there didn't CHOOSE to do so, and sure enough, the place is littered with fungus, lava, and plenty of gloom. Many surface towns also have monster-infested sewers.
  • Final Fantasy IV contains an enormous, open-space underworld, populated by dwarves.
  • The Locust from Gears of War live in a vast series of underground caverns known as The Hollow.
  • The Myst series of PC games gradually reveals that the lost city of D'ni is in a five-mile-wide cavern somewhere beneath a vast stretch of desert in New Mexico note . One game in the series actually permits a virtual exploration of D'ni itself.
  • The Warcraft games have their share of underground caverns.
    • Azjol-Nerub, the capital of the Nerubian civilization, is a sprawling underground labyrinth that stretches across much of the continent of Northrend. The part where the Nerubians used to live is called the Upper Kingdom, and below that is the Old Kingdom, which consists of even deeper tunnels populated by nameless horrors and one of the Old Gods, which was confirmed to be Yogg-Saron in the Wrath of the Lich King expansion.
    • The first 40-man raid instance in World of Warcraft, Molten Core, is a huge lava-filled cavern located deep under Blackrock Mountain. It's home to elementals, lava giants, core hounds and Ragnaros, the elemental lord of fire.
    • The Undercity, the vast subterranean home base of the Forsaken, built underneath the ruins of another city.
  • The Sierra adventure game Torin's Passage has no less than four separate worlds Beneath the Earth, each one nested inside the other. In the outermost world, being banished to the Lands Below is a form of capital punishment.
  • The original Zork text-based game features exploration of the Great Underground Empire.
  • Dwarf Fortress has implemented no fewer than three levels of world-spanning underground cavern systems, home of mushroom forests, tribes of animal people and some very weird and hostile monsters, with each layer getting progressively nastier than the last. Dig down past all three of those, and you'll find a great sea of magma and "semi-molten rock". And beneath that, if you can contrive to get at it, is Hell, which can be surprisingly easy to reach, provided you can find the right veins of mineable rock and have a decidedly casual attitude towards being slaughtered by sheep monsters made of ice.
  • Master of Orion 2 has the Subterranean racial trait. Being a tunneling sort means that your colonies can support a greater population, and ten points are added to to trooper effectiveness when defending against a ground invasion.
  • The underground in Touhou has its own city, and is also stated to be a former hell. Currently inhabited by youkai that were considered creepy and unpleasant by other youkai. Not really the nicest place around.
  • Age of Wonders has two map layers (until Shadow Magic added the third), with caves allowing access to the Underground level.
  • Baldur's Gate II has the Underdark, a vast subterranean labyrinth covering much of the world.
  • The Underdark is revisited in the Neverwinter Nights Expansion Pack fittingly titled Hordes of the Underdark. Several fan-made NWN modules feature the location prominently, as well: an Underdark essentially identical to the one found in Forgotten Realms forms a bulk of Part Two of A Dance with Rogues, despite its setting being otherwise an original Constructed World.
  • The Dragon Age series features the Deep Roads, a vast subterranian network of artificial caverns and passages dug out by the dwarves in the heyday of their civilization. It had once consisted of hundreds of underground cities named "thaigs" and the miles-long tunnels connecting them, but ever since the First Blight, all but two of them have been overrun by the darkspawn. One thaig, Orzammar, is the capital of modern dwarf civilization and is visited in Dragon Age: Origins.
  • The Legend of Zelda:
    • The Legend of Zelda: Oracle Games feature the Subrosians, who live in the realm of Subrosia right underneath Holodrum.
    • The Legend of Zelda: Skyward Sword's backstory explains how The Dark Times in Hyrule began when a great army of demons emerged from the earth and ravaged the land in their campaign to obtain the Triforce.
    • The Legend of Zelda: Breath of the Wild says that Calamity Ganon emerged from beneath Hyrule Castle a century ago to unleash its genocidal rage upon the land. You end up fighting Ganon in the giant underground Sheikah laboratory where it had presumably been sealed up to that point.
  • Quake has a secret level named "The Underearth".
  • Dark Souls has the player spend a lot of time in a variety of underground areas, such as demon infested lava ruins and the Tomb of the Giants.
  • Minecraft:
    • In order to get anything done in the game, you need to create labyrinthine tunnels deep underground while mining, which is more or less inevitably going to result in a complex maze of tunnels extending from your base — and you need to burrow quite deep to get to the best ore.
    • Natural caves are procedurally generated like every other landform, and get bigger and more extensive the deeper down you go, together with an increasing likelihood for separate caves having connections with each other. Near-surface caves are fairly small and modest, but the ones near the bottom of the game world can get very big indeed, and are almost always interlinked, resulting in huge underground networks. Naturally, these caves are pitch dark unless you light them up with torches, and as such are crawling with hostile monstersnote . Underground lakes and rivers are also common, as are lakes and waterfalls of lava that provide the only natural light down there.
  • The Elder Scrolls V: Skyrim has Blackreach, a giant cave the size of a small country, housing an ancient Dwemer city complex. This, as well as other Dwemer ruins throughout Skyrim, have largely been taken over by the Falmer, a race of subterranean goblin-like creatures who were once the graceful Snow Elves but were taken in and twisted by the Dwemer when their race was threatened by the invading Nords.
  • Nearly every single Tomb Raider game will have Lara Croft explore an underground cavern at some point that are filled with traps, water, lava, wild animals, and sometimes a T-Rex. While she also explores underground urban areas as well, caves are usually more common in the franchise.
  • Vivid Conceptions: Beneath the Earth is where the miniature Bantam civilization dwelled before dinosaurs even existed, and where the game takes place.
  • Turok 2: Seeds of Evil has the Lair of the Blind Ones, whose centuries spent in darkness has rendered them eyeless as well as giving them a lethal sensitivity to sunlight.
  • The Heroes of Might and Magic franchise has cavernous underground levels as a series fixture, sharing many resources and sites you can visit with the surface world, and having unique ones too. There's usually an evil faction that specializes in being there (named Dungeon in several of the games) and other (mostly evil) factions might be more or less at home down there. From map to map, the caverns range from nothing to a vast, sprawling system that has as much open space as the surface world or even more.
  • The majority of Deadly Rooms of Death takes place below the surface. Beethro is exploring King Dugan's 25-level dungeon when he finds passages leading to even deeper dungeons, and eventually to the Rooted Empire.
  • Most of Cry of Fear: the Hole takes place underground, where Simon wanders dark mine tunnels and strange mazes.
  • In Dominions, the nation of Agartha is based on this. Initially populated by the native Pale Ones, humanoids that can grow to gigantic size, they begin to die out and are replaced by humans who take to worshiping them as the Ages progress.
  • Deep below the surface of Britannia in Ultima V is the Underworld, a wild neverland of linked caverns and river rapids that collapses at the game's end. In Ultima VI you can proceed through the ruins and reach the other side of the flat earth.
  • Lost Ember has "moles"note  who live in and around a network of tunnels. When transformed into one, you can also dig your way under obstacles and create your own new tunnels.
  • In The New Order Last Days Of Europe, warlords of the Black League in Omsk can establish a complex metro system designed to protect their population from Nazi German nuclear attacks.
  • In The Legend of Heroes: Trails of Cold Steel IV, it is revealed that the location of the Black Workshop is at one thousand meters below a mountain range that can be seen from the town of Milsante. It's where Rean's held as a prisoner at the climax of Cold Steel III and throughout all of act 1 of IV.

  • From Sluggy Freelance:
  • Girl Genius has Deepdown. It's big.
    Lars: big can these tunnels be?
    Maxim (ex-cavalrymanjager): How big?! Ho ho! [...] it took us two years to get outta dose caverns.
  • The dragon cities in the comic Dragon City that aren't in sewers, are in caverns, much like Dragon City Chicago (before the cave-in), where the webcomic primarily takes place. In fact, this is how dragons escaped the mass extinction that wiped out the dinosaurs.
  • Woo Hoo features a vast Subterrain, a network of caverns, subways and urban areas, formed when a section of the city sank underground during an earthquake.
  • 25th Baam from Tower of God was trapped for years inside an underground cavern before the plot started.
  • In Everyday Heroes, Hornswoggle and family live in an Absurdly Spacious Sewer.
  • This is the main setting of Drowtales, where the bulk of Drow civilization consists of a handful of large subterranean city-states within large caverns in an extensive underworld, separated by large stretches of stony wilderness home to isolated outposts, driders, degenerate Drow Mole Men, and the few Dwarf nations the Drow didn't wipe out. It was created alongside the sky world during the first of two apocalyptic wars waged by ancient elves when a substantial piece was broken from one of the moons and fell to earth, with the underworld being, in essence, the cracks in the world that impact caused. At least one section, the Nidavellir, is open to the skynote  but filled with a sea of fog. There's also a second underworld under a different continent from the main one, ruled by its own Drow nation, Hel. It's not a nice place.
  • The Underground in Sam & Fuzzy is a massive, world-spanning set of caves complete with underground cities, roads and small communities. It's home to practically everything supernatural that humanity has ever thought was real, mixed with some sci-fi elements as well like artificial robots.

    Web Original 

    Western Animation 
  • Avatar: The Last Airbender:
    • The Earth Kingdom's capital of Ba Sing Se was once a subterranean city built within crystal catacombs carved out by Earthbenders. Following expansion, the caverns were abandoned and the lost city is now know as Old Ba Sing Se.
    • The Fire Nation capital (built in the caldera of a dormant volcano) also has a series of underground tunnels, which are mainly used as a defense bunker in case of emergencies.
  • Chip 'n Dale Rescue Rangers: The leprechauns live in underground places, which in the case of the leprechaun king Darby Spree can be pretty spacey.
  • My Little Pony:
    • My Little Pony 'n Friends has the Dell Dwellers from "Mish Mash Melee" and the Kingdom of the Lava Demons from "Quest of the Princess Ponies".
    • My Little Pony: Friendship Is Magic has the Diamond Dogs from "A Dog and Pony Show", a group of subterranean dog-men who inhabit a labyrinthine system of tunnels and large caves. There is also a fairly extensive system of interconnected caves running beneath the outskirts of Ponyville and the Everfree Forest, consisting of a long tunnel studded with gems, a large cave filled with plant life and lit by a cluster of giant Glowing Gems on its roof, several mazelike tunnels and the cave of the mirror pool.
  • Mighty Max gives us Skull Mountain, located deep underground and surrounded by magma, which is Skullmaster's abode, having been banished there thousands of years ago.
  • Ned's Newt has trolls living beneath the Earth's surface, who sometimes try to Take Over the World, only to be stymied by the protagonists.
  • The New Adventures of Superman: In "The Neolithic Nightmare", Jimmy Olsen falls into an underground pocket populated by malevolent creatures, including dragons, rocs, and giant spiders.
  • The Carlocks from Regular Show live in caverns that extend from the park's crash pit and subsist on whatever is thrown into the pit, mostly food left in the busted up old cars.
  • Star Wars: The Clone Wars:
    • In "Mercy Mission", R2 and 3PO end up wandering about the cave system beneath the surface of planet Aleen. There they encountered the inhabitants, who included tree-like humanoids and the frog-like fairy Orphne, were causing earthquakes, trying to seal the breach between them and the surface, because surface air was poisonous to them.
    • In "Bounty", Asajj Ventress and Boba Fett's crew visit a planet, Quarzite, which is inhabitable only below the surface. At the time the two native species, the Belugans and Kages, are engaged in a Civil War.
  • The Mole People featured in The Tick are actually a peaceful but weird group who didn't want to conquer the surface world but to just take a vacation. The Lava men on the other hand...
  • Trolls from Trollhunters originate from deep within the Earth, just as humans come from the surface. Because most Trolls species turn to stone when in contact with daylight, Trolls usually dwell in vast caverns and other underground spaces.

    Real Life 
  • Deep caverns permeated by sulfur gases are one of the major refuges for Archaea, ancient prokaryotes that dominated the primordial Earth before oxygen levels rose in the atmosphere. A far cry from dinosaurs, but still a "lost world" ecosystem that persists underground, billions of years after being displaced from much of the planet's surface.
  • Karst topography, formed by water slowly eroding through soluble bedrock over long periods of time, tends to produce impressively extensive cave systems. The largest and most well-known of such caves is probably Mammoth Cave in Kentucky.


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