History Main / UnderwaterCity

** In rather odd book (#35, ''The Mutation''), the heroes, plus [[BigBad Visser Three]], get trapped in a city in an underwater cave. The inhabitants are amphibious mutants whose race is dying, which means that they harvest any humans who sink for DNA.

* In the ''Literature/{{Tempest}}'' trilogy, there are a number of these, inhabited by either selkies or merfolk. Inhabitants live in either caves or in buildings made of stone, coral, and shells. After Tempest moves underwater, she spends most of her time in Coral Straits, the capital city of Queen Hailana's territory.

* The "Undersea" trilogy by Creator/FrederikPohl and Creator/JackWilliamson (''Undersea Quest'', ''Undersea Fleet'', and ''Undersea City'') has underwater domed cities protected by AppliedPhlebotinum ("Edenite" forcefields). Think ''Literature/SpaceCadetHeinlein'' done underwater.

* ''VideoGame/{{Undertow}}'': With most landmasses gone due to mass flooding, humanity now survives by living in [[https://www.gamespot.com/a/uploads/original/mig/1/1/7/6/851176-939205_20080207_004.jpg enclosed facilities]] along the ocean floor, as do the Nemonians, but the latter presumably did so long before the calamity given [[Literature/TwentyThousandLeaguesUnderTheSea who]] their leader is.

See also CityOnTheWater for cities atop the water instead of underneath.

** ''Anime/DoraemonFilmSeries''
** ''Anime/DoraemonNobitaAndTheCastleOfTheUnderseaDevil'' have Doraemon and friends deciding to visit the world under the Atlantic Ocean (which they can adapt in thanks to Doraemon's gadgets, as usual). It was there they end up in the underwater kingdom of Mu, and find out the neighboring land of Atlantis is about to invade the surface.
** ''Anime/DoraemonNobitasGreatBattleOfTheMermaidKing'' sees the gang visiting Planet Aquadia, a world made entirely of seas, with cities built on the ocean floor and populated by merfolk.
* The Fishman Island in ''Manga/OnePiece'' is actually a big mass of land floating in a 2-layer resin bubble, underwater. The light source come from the mystical Sunlight Tree Eve, which transfers sunlight from the surface to the ocean deep.
* ''Anime/NagiAsuALullInTheSea'' has Shioshishio, a small town of ApparentlyHumanMerfolk near a Japanese town on the coast. There's substantial friction between the neighbours over things like fishing rights.

* ''Anime/PokemonRangerAndTheTempleOfTheSea'' features Samiya, the titular Sea Temple floating beneath the ocean surface in a bubble of air.

* Both Franchise/MarvelUniverse and Franchise/TheDCU have versions of Atlantis, although in both cases Atlantis is a big place with multiple cities.
* ''ComicBook/{{Aquaman}}'': In one arc, half of San Diego slides into the sea following a massive earthquake... and those who survive it instantly adapt to underwater conditions.
* ''ComicBook/WonderWoman1942'': Venturia, an Atlantean outpost city once ruled by the cruel Franchise/WonderWoman villain Queen Clea, is an underwater city with a badly damaged infrastructure due to their former ruler's incompetence.

* ''Film/CityBeneathTheSea'' a MadeForTVMovie from the 70s about two futuristic divers discovering an underwater city that must be protected from alien forces. It was intended as a pilot for a TV series (produced by Irwin Allen) but never got picked up.
* ''Film/TheCityUnderTheSea'' (1965), AKA ''War Gods of the Deep'', a B-movie from TheSixties features a MadScientist keeping a girl hostage in a city full of advanced humans with extended lifespans.
* ''Film/TheUnderwaterCity'' (1962) details a group of people testing out experimental underwater housing - and disaster strikes when the settlement caves in.
* ''Film/CaptainNemoAndTheUnderwaterCity'' is a 1968 {{Steampunk}} film about a group of people encountering Captain Nemo, who had developed several advanced submarines aside from the ''Nautilus'' and had created an underwater city for his crewmen and their families.
* Otoh Gunga, home of the Gungans as shown in ''Franchise/StarWars: Film/ThePhantomMenace'', is made out of a large number of sealed-off, interconnected domes at the bottom of a large lake.
* ''Film/TheAbyss'', in which the [=NTIs=] have a very large habitat on the ocean floor. (Whether it's a city or an enormous starship is never really made clear.)

* ''Literature/TheShadowOverInnsmouth'' by Creator/HPLovecraft has Y'ha-nthlei, of the "titanic sunken porticos" and "labyrinths of weedy cyclopean walls." Located off the coast of [[LovecraftCountry Massachusetts]] and home to the Cthulhu-worshipping [[FishPeople Deep Ones]].
* Creator/IsaacAsimov's ''Literature/LuckyStarrAndTheOceansOfVenus'': Colonies on {{UsefulNotes/Venus}} are built in underwater domes due to 1950s science agreeing that it is essentially [[VenusIsWet a planetary ocean]].
* Also by Creator/IsaacAsimov, the short story "Waterclap" is about Ocean-Deep, a settlement on the deep-sea floor, and goes into some detail about how it operates. At the time of the story it only has fifty inhabitants and they don't spend more than six months there at a time, but it's in the process of expanding to become a permanent settlement, and it's stated that there are already numerous settlements on the continental shelf. [[spoiler:The DecoyProtagonist, a visitor from a colony on the Moon, is plotting to destroy it, as he fears it will lead to Earth's population focusing on settling the ocean and abandoning further expansion into space.]]
* Michael Reaves and Steve Perry's novel ''{{Dome}}'', which is set in a futuristic underwater lab complex.
* Underwater colonies are a significant part of the backstory of the ''Literature/MyNameIsLegion'' story "The Eve of RUMOKO".
* A city of cray (lobster-centaurs) is featured in Creator/ChinaMieville's ''Literature/TheScar''.

* The great city of hi'Leyi'a on the planet Pacifica, in the Literature/StarTrekNovelVerse. First mentioned in ''Literature/StarTrekTitan'', it finally appeared in ''[[Literature/StarTrekTheNextGenerationRelaunch Losing the Peace]]''.
* Handled as realistically as possible in "Ocean on Top" by Creator/HalClement. A colony of humans is established on the ocean floor, using geothermal power to provide light and a specially-made oxygen-carrying dive fluid in place of air. But since the humans are less dense than water, the humans have to wear weights if they want to stay on the bottom or even have neutral buoyancy. They sleep tied to the ceilings of their buildings.
* Somewhereinitaly in ''Literature/AlmostNight''. There was also a city called Somewherenotinitaly, but it was destroyed by the [[Franchise/CthulhuMythos Deep Ones]].
* The "Undersea" trilogy by Creator/FrederikPohl and Creator/JackWilliamson (''Undersea Quest'', ''Undersea Fleet'' & ''Undersea City'') have underwater domed cities protected by AppliedPhlebotinum ("Edenite" forcefields). Think of ''Literature/SpaceCadetHeinlein'' done underwater.
* ''{{Literature/Animorphs}}'' has an odd book where the heroes, plus [[BigBad Visser Three]], get trapped in a city in an underwater cave. The inhabitants are amphibious mutants whose race is dying, which means that they harvest any humans who sink for DNA.
** They also visit the City of Worms (it's nicer than it sounds) on Leera, an ocean world inhabited by frog-like aliens.
* In ''{{Literature/Everworld}},'' Poseidon and Neptune both have underwater cities, and they're fighting over Atlantis. We mostly see Neptune's city, where water can be drained, or humans made amphibious, based on the god's whim. ([[MadGod This is not encouraging]].)
* In ''Literature/UnderneathAMerfolkTale'' the merfolk population lives in The City. The merfolk in the story actually live in land and have little dealings with it, although their history and their reasons for leaving it are part of the plot.

* ''Literature/AndThenITurnedIntoAMermaid'': In the second book, Margot takes Molly to look at Balaena, the capital city of the queendom of Meire that was mostly abandoned due to pollution, through a telescope. Molly sees towering buildings and ancient shipwrecks, lit up by the electroreceptive fish the mermaids once used to power the city.

* ''Literature/MermaidsOfErianaKwai'': Lysi grew up in King Adaro's capital city, Utopia, which is near the Aleutian Islands. In ''Ice Kingdom'', Lysi and Meela travel to Queen Medusa's capital city in the Atlantic, which is full of kelp archways and stone buildings covered in plant life that reach higher than the surface. Lysi is amazed by how much more vibrant and colourful it is than Utopia.
* In ''Literature/BadMermaids'', the mermaid queendom of Hidden Lagoon has five cities: Swirlyshell, the largest city, where the buildings resemble giant spiral shells; Oysterdale, where the richest mermaids live in {{Palatial Sandcastle}}s; Hammerhead Heights, which is located in a canyon and is inhabited by both [[UnscaledMerfolk shark mermaids]] and actual sharks; Anchor Rock, which is smaller and colder than the other cities and decorated with shipwrecks and human trash; and Lobstertown, home of the Lobsterdome and Hidden Lagoon's most successful [[FictionalSport shockey]] team. There's also the Kelp Forest, a trendy suburb of Hammerhead Heights whose economy is based on kelp products.
* ''Literature/TheVazulaChronicles'': The triple kingdoms consist of Tilssted, Hemssted, and Skulssted, which were once separate cities but have merged into one large metropolis. Merpeople in all three mostly live in stone houses similar to the ones found on land. Merletta trains in the Center of Culture, a complex of spectacular underwater skyscrapers in the center of the triple kingdoms. To her underwater cities are normal while [[FaeriesDontBelieveInHumansEither humans are a myth]], so when she discovers Vazula she's astonished by the sight of stone buildings far away from water.

* ''Series/StargateAtlantis'':
** In the first episode, the city is discovered to be underwater, having been submerged by the Ancients to escape constant orbital bombardment from the Wraith. In a subversion of the GoneHorriblyWrong situation mentioned above, when the shield fails, the city surfaces.
** In a DoubleSubversion, [[spoiler:It didn't happen the first time around: In an alternate timeline, the city was flooded, and Dr. Weir escaped drowning in a [[TimeTravel time-traveling ship]]; she then convinced Ancient scientist Janus to add the fail-safe]].

* ''Series/SeaQuestDSV'' is set in a world where the ocean floor has been so heavily colonized that there are whole underwater ''nations.''
* In the cartoon segments of ''Series/TheAquabatsSuperShow'', the band tries infiltrate an underwater city beneath the moon's surface to save Jimmy the Robot.
* In ''Series/StarTrekTheNextGeneration'', still reeling from his recent assimilation by the Borg, Picard is briefly tempted in "Family" to quit Starfleet and join the Atlantis Project, who are aiming to build one of these on the floor of the Atlantic Ocean.
* In ''Series/StarTrekVoyager'', ''Voyager'' encounters a giant spherical ocean floating in space, with alien cities inside it. The whole thing is held together by some ancient Precursor machine, which is starting to break down.
* ''Series/CityBeneathTheSea'' was at a TV movie created for television as a PoorlyDisguisedPilot by Creator/IrwinAllen.

* According to "Year 3000" by Music/{{Busted}}, also covered by Music/TheJonasBrothers, this will be the default situation in TheFuture. Apparently there'll also be no nudity taboo either.
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* ''TabletopGame/{{Shadowrun}}'': In the 2nd Edition supplement ''Portfolio of a Dragon: Dunkelzhan's Secrets'', the last will of the titular dragon left a bequest of five million nuyen to the first party to establish a self-sustaining community of at least 100 persons on the ocean floor. Yamatetsu Corporation eventually won the bequest with their [=SoaTome AquaDomes=].
* ''TabletopGame/TranshumanSpace'' has Elandra, an Australian-founded "free city" under the Pacific. It's more of a town than a city, really, but a respectably-sized one.
* Underwater cities have cropped up occasionally in the lore of ''TabletopGame/Warhammer40000''.

* In the 20th Anniversary edition of ''TabletopGame/MageTheAwakening'', the Avatar Storm cut off the Technocratic Union from bases maintained in Horizon Realms. In order to have bases of operation relatively secure from the prying eyes of the Sleepers as well as the Traditions, several of the [[UnderwaterBase Underwater Bases]] previously maintained solely by the Void Engineers have been converted (or are in the process of conversion) into full-on cities with representatives from all of the Union's Conventions.
* In ''TabletopGame/{{Cyberpunk}}'', these are collectively referred to as The Deepdown. Consisting of domes and facilities located on the continental shelves, these were built by various corporations and mostly engage in farming phytoplankton, fishing and undersea mining. During the chaos of the Fourth Corporate War, they severed ties with their corporate founders and cut off all contact with the surface, going so far as to build powerful cloaking devices that prevent any radar systems from finding them. The only contact they have now is through the [[CityOnTheWater Drift Nations]] that occasionally trade with them.

* ''[[VideoGame/AnnoDomini Anno 2070]]'' has underwater cities...except they aren't actually cities. Rather, they're underwater plateaus (implied in-game to be parts of our world submerged by climate change) which all three major factions can build farms and factories on. These largely-automated facilities provide supplies which are rare or nonexistent abovewater, making them a key part of the middle and late-game. The game's lesser faction, the S.A.A.T. (Scientific Academy for Advanced Technologies) specialises in building and working with such settlements, an attribute which was further developed in the game's expansion, ''The Deep Sea''.
* ''VideoGame/{{Aquaria}}'' has Mithalas City, which has long since been completely ruined after [[spoiler: a PathOfInspiration corrupted its patron deity into a horrible monster. Guess what you end up fighting in the ruined cathedral.]]

%%* The ''VideoGame/CallToPower'' series has sea cities.

* ''VideoGame/{{Starbound}}'': The [[FishPeople Hylotl]] live in these. And it [[http://imgur.com/a/B5sny looks awesome.]]

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* In ''Roleplay/TheGamersAlliance'', Adlivun is a thriving underwater city populated by merfolk known as merrows.
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* ''WesternAnimation/{{Futurama}}'' featured the Lost City of UsefulNotes/{{Atlanta}} -- a joke on {{Atlantis}}, of course -- which was turned into a CityOnTheWater to attract more tourism, but became overloaded with buildings and construction and sank. The citizens who stayed behind ended up evolving into [[OurMermaidsAreDifferent mermaids and mermen]] by the 3000's, thanks to the caffeine from the Coca-Cola plant (somehow) speeding up their evolution.
* ''WesternAnimation/{{Sealab 2020}}'' opening credits.
-->This is the year two thousand and twenty. The place is the Challenger seamount, the top of an underwater mountain, a complex beneath the sea. 250 men, women and children live here, each of them a scientist-pioneer. For this is our last frontier, a hostile environment which may hold the key to tomorrow. Each day these oceanauts meet new challenges, as they build their city beneath the sea. This is Sealab 2020.
* ''WesternAnimation/{{Sealab 2021}}'' is a parody of the original ''Sealab 2020'', where nearly everyone working in the undersea city is some combination of [[TooDumbToLive stupid]] or [[CloudCuckoolander crazy]].
%%* The ''WesternAnimation/{{Superjail}}'' episode "Superbar".
* ''WesternAnimation/{{Jabberjaw}}'' took place in a future with a number of underwater cities, where the Neptunes would perform before stumbling on some misadventure.

* They visited Atlantis on ''WesternAnimation/TheFairlyOddParents.'' Also, Clevelantis.
* ''WesternAnimation/{{King}}'' had Bubble Town, the capital of the nation of Undersea, ruled over by the despotic Cousin Tess.
* ''WesternAnimation/TheAdventuresOfSuperMarioBros3'' featured the city of Mertropolis in the episode "The Ugly Mermaid". It was a bizarre case in that the city was inside a large dome filled with air, despite the native merfolk not being able to breathe air, which meant they walked around wearing fishbowls filled with water.
* ''WesternAnimation/SamuraiJack'': The episode "[[Recap/SamuraiJackS1E9JackUnderTheSea Jack Under the Sea]]" features the underwater city of Oceanus, home of an amphibious alien tribe called the Triseraquins, built as a system of waterproof domes on top of high-tech towers. It used to be a CityOnTheWater instead, but Aku banished it beneath the ocean to where it is now. [[spoiler:It returns to the surface by the end of the episode]].
* ''WesternAnimation/TheLittleMermaid1992'': In addition to Atlantica, there is also Eel-Ectric City - a metropolis that's "so hopping it's always bopping".

* The "Undersea" trilogy by Creator/FrederikPohl and Creator/JackWilliamson (''Undersea Quest'', ''Undersea Fleet'' & ''Undersea City'') have underwater domed cities protected by AppliedPhlebotinum ("Edenite" forcefields). Think of Creator/RobertAHeinlein's ''Literature/SpaceCadet'' done underwater.

* ''Aquarius Mission'' by Creator/MartinCaidin has a city of ApparentlyHumanMerfolk who live in the deepest part of the ocean and have some pretty advanced OrganicTechnology.

* ''Anime/DoraemonNobitaAndTheCastleOfTheUnderseaDevil'' have Doraemon and friends deciding to visit the world under the Atlantic Ocean (which they can adapt in thanks to Doraemon's gadgets, as usual). It was there they end up in the underwater kingdom of Mu, and find out the neighboring land of Atlantis is about to invade the surface.