Follow TV Tropes


Underwater City

Go To
Complete with sea-floor highways!

"It seemed a sure bet that by the early '70s we'd be flipping a coin as to whether we'd be spending our holidays on the Moon or at the Poseidon Hilton on the bottom of the Caribbean."

Not just Underwater Ruins or an Underwater Base, but an entire city of people living and "breathing" underwater. It's usually created with futuristic technology or powerful magic, and a popular depiction is to have a fully surviving Atlantis with domes and/or water breathing Fish People or Apparently Human Merfolk. Similarly, these cities may crop up as a way of surviving in a Flooded Future World. Usually, though, it's a modern attempt at colonizing the ocean floor, or a villain's secret lair. There may be multiple locations connected by undersea tunnels.

As might be expected, living in such a precarious location makes these cities inordinately prone to having something go horribly wrong, be it sabotage causing the dome to break, an undersea volcano activating, or other disasters.

Having a several kilometer-wide glass dome is impractical in real life, but Hollywood follows the Rule of Cool, so huge glass domes are the norm in stories. In fiction, the "sky" of the underwater city is filled with swimming fish. In some stories, the dome is a force field that uses a high-tech or magical Applied Phlebotinum.

See also City on the Water for cities atop the water instead of underneath, and Sunken City for cities that were built above the water level but were later submerged (and are usually no longer inhabited).

Compare Underground City.


    open/close all folders 

    Anime & Manga 
  • Daphne in the Brilliant Blue: The main cities of the aquatic New Eden were originally Underwater Cities created to escape the apocalypse. Heroine Maia is the last survivor of one of the cities which was destroyed before it could surface.
  • In The Mysterious Cities of Gold, the third City of Gold rests underwater.
  • Nagi-Asu: A Lull in the Sea has Shioshishio, a small town of Apparently Human Merfolk near a Japanese town on the coast. There's substantial friction between the neighbours over things like fishing rights.
  • The Fishman Island in One Piece 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.

    Comic Books 
  • Both The DCU and the Marvel Universe have versions of Atlantis, although in both cases, Atlantis is a big place with multiple cities.
  • Scion: Ethan discovers an underwater city built by an aquatic sub-species of the Lesser Races who were able to escape their lives of slavery.
  • Wonder Woman (1942): Venturia, an Atlantean outpost city once ruled by the cruel Wonder Woman foe Queen Clea, is an underwater city with a badly damaged infrastructure due to their former ruler's incompetence.

    Fan Works 
  • A Diplomatic Visit: After being mentioned in the first story, the sequel Diplomat at Large has Twilight visiting Seaquestria in the eastern oceans, ruled by the seapony Queen Novo and home to a mix of seaponies and transformed hippogriffs, and Aquastria in the western oceans, ruled by merlion King Leo and inhabited by a mix of merlions, seaponies and mermares.
  • FFS, I Believe in You: The majority of Zora's Domain consists of buildings and artificial caverns built deep below the waters of their lake; the in-game Domain is essentially the topmost levels of the city, built in the air to facilitate contact with the rest of Hyrule's races.
  • The Institute Saga has Sanctuary, a domed refuge which the Morlocks move into, followed by the Labrynth Clan.
  • Lost Cities: The seaponies of the Endless Ocean lived in a city built at the bottom of the Starlight Trench, and housed within a great palace spun from nacre. It's also mentioned that Aquastria, another submarine seapony city, still exists under the Eternal Ocean on the other side of the continent.
  • Nobledark Imperium: A number of pressurized dome cities existed beneath what was left of Old Earth's oceans, inhabited by hardy folk who had to adapt themselves to life in an environment where even a small technical problem could cause a lot of deaths. The soldiers recruited from there during the Unification Wars, the Lucifer Blacks, were known for their iron discipline and for fighting in full-body pressure suits. During the Great Crusade, the Blacks and their descendants mostly settled ocean worlds reminiscent of their old homes.
  • Pokédex: The Jellicent are the keepers of one beneath a massive, Jellicent-shaped dome, made out of shipwrecks and flotsam, lit and warmed by underwater vents and populated by sailors kidnapped en masse when their ships pass through the Jellicent's territory. The purpose for this seems to be so that the Jellicent can have access to human technology.

    Film — Animated 

    Film — Live-Action 
  • In The Abyss, 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.)
  • Captain Nemo and the Underwater City is 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.
  • City Beneath the Sea is 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.
  • The 1965 B-movie The City Under The Sea (1965), a.k.a. War Gods of the Deep, features a Mad Scientist keeping a girl hostage in a city full of advanced humans with extended lifespans.
  • Otoh Gunga, home of the Gungans as shown in The Phantom Menace, is made out of a large number of sealed-off, interconnected domes at the bottom of a large lake.
  • Ultraman Cosmos 2: The Blue Planet: The Alien Gyashis, an underwater-based alien race who crashed on Earth decades ago after losing their planet to the Scorpiss horde, ends up living under the earth's oceans which can be accessed from a portal on the water's surface.
  • The Underwater City (1962) details a group of people testing out experimental underwater housing — and disaster strikes when the settlement caves in.

  • Somewhereinitaly in Almost Night. There was also a city called Somewherenotinitaly, but it was destroyed by the Deep Ones.
  • And Then I Turned Into a Mermaid: 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.
  • Animorphs:
    • In rather odd book (#36, The Mutation), the heroes, plus 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.
  • Aquarius Mission by Martin Caidin has a city of Apparently Human Merfolk who live in the deepest part of the ocean and have some pretty advanced Organic Technology.
  • In Attack From Atlantis by Lester del Rey, a submarine crew discover an ancient underwater civilization.
  • In Bad Mermaids, 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 Sandcastles; Hammerhead Heights, which is located in a canyon and is inhabited by both 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 shockey team. There's also the Kelp Forest, a trendy suburb of Hammerhead Heights whose economy is based on kelp products.
  • In Bounders, the Alkalinians live on an ocean planet in a series of underwater buildings, some anchored to the floor and some bobbing in the current, connected by clear tubes.
  • Michael Reaves and Steve Perry's novel Dome is set in a futuristic underwater lab complex.
  • In 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. (This is not encouraging.)
  • Forbidden Sea: The Sea Prince lives in a palace in Siarah, a city thousands of feet under the sea, lit by magic orbs that draws energy from the surrounding water. Most merfolk live in towering structures that consist of many houses stacked on top of each other.
  • Lucky Starr and the Oceans of Venus: Colonies on Venus are built in underwater domes due to 1950s science agreeing that it is essentially a planetary ocean.
  • Mermaids of Eriana Kwai: 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.
  • The Merman's Children: The merfolk of Liri take advantage of the water's support to build delicate houses of seaplants and ivory that would collapse on land. One exception is King Vanimen's hall, which is made of stone and coral.
  • Underwater colonies are a significant part of the backstory of the My Name Is Legion story "The Eve of RUMOKO".
  • Handled as realistically as possible in "Ocean on Top" by Hal Clement. 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.
  • Real Mermaids: The mer pod in Port Toulouse Bay lives in a village consisting mostly of low-lying caves in an underwater valley.
  • A city of cray (lobster-centaurs) is featured in The Scar.
  • The Shadow Over Innsmouth has Y'ha-nthlei, of the "titanic sunken porticos" and "labyrinths of weedy cyclopean walls." Located off the coast of Massachusetts and home to the Cthulhu-worshipping Deep Ones.
  • The great city of hi'Leyi'a on the planet Pacifica, in the Star Trek Novel 'Verse. First mentioned in Star Trek: Titan, it finally appeared in Losing the Peace.
  • In the Tempest (2011) 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.
  • In Underneath - A Merfolk Tale, 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.
  • The Undersea Trilogy by Frederik Pohl and Jack Williamson (Undersea Quest, Undersea Fleet, and Undersea City) has underwater domed cities protected by Applied Phlebotinum ("Edenite" forcefields). Think Space Cadet (Heinlein) done underwater.
  • The Vazula Chronicles: 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 humans are a myth, so when she discovers Vazula, she's astonished by the sight of stone buildings far away from water.
  • Isaac Asimov's 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. The Decoy Protagonist, 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.

    Live-Action TV 
  • In the cartoon segments of The Aquabats! Super Show!, the band tries infiltrate an underwater city beneath the moon's surface to save Jimmy the Robot.
  • ORCA in Ocean Girl is halfway between this and Underwater Base. The ORCA City project may be closer to this trope.
  • SeaQuest DSV is set in a world where the ocean floor has been so heavily colonized that there are whole underwater nations.
  • Stargate Atlantis: 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 Gone Horribly Wrong situation mentioned above, when the shield fails, the city surfaces. In a Double Subversion, it didn't happen the first time around: In an alternate timeline, the city was flooded, and Dr. Weir escaped drowning in a time-traveling ship; she then convinced Ancient scientist Janus to add the fail-safe.
  • In the Star Trek: The Next Generation episode "Family", still reeling from his recent assimilation by the Borg, Picard is briefly tempted to quit Starfleet and join the Atlantis Project, who are aiming to build one of these on the floor of the Atlantic Ocean.
  • In the Star Trek: Voyager episode "Thirty Days", 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.

  • According to "Year 3000" by Busted, also covered by The Jonas Brothers, this will be the default situation in The Future. Apparently, there'll also be no nudity taboo either.

  • In The Gamer's Alliance, Adlivun is a thriving underwater city populated by merfolk known as merrows.

    Tabletop Games 
  • In 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 Drift Nations that occasionally trade with them.
  • Several Dungeons & Dragons settings include undersea civilizations of merfolk, tritons, sahuagin or the like; some of these use air-filled domes as housing for surface-dwelling visitors. The Known World/Mystara campaign setting has the Kingdom of Aquas, which was once part of the Empire of Alphatia.
  • In the 20th Anniversary edition of Mage: The Awakening, 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 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.
  • Mechanical Dream: The Emovans are a fully aquatic species, and for the most part live in cities at the bottom of the world's subterranean oceans.
  • In New Horizon, Aquilon's Reach has multiple underwater cities, as well as some atop glaciers. Unsurprisingly, they also boast the best navy in game.
  • Numenera: Several exist, some in fairly shallow parts of the sea and some in the blackest depths. Their inhabitants collectively refer to these places as oceia.
    • Joria is a city built on the back of an enormous crustacean called a granthu, which moves in a roughly constant orbit around the ocean floor. The city is partly open to water, and inhabited by a species of amphibious humanoids called Jorians. The Jorians believe that there are other cities of their kind on the backs of other granthus, following their own orbits somewhere in the global ocean, and put in a great deal of time and effort in searching for them.
    • The City of Rust is a large settlement on top of a massive slab resting on the ocean floor, which gets its name from the rust-red metal making up its buildings. It's mostly inhabited by a species of aquatic aliens called the skeane, and watched over by four massive and fickle AIs that its inhabitants worship as gods.
    • Ahmas is a city in the darkest depths of the ocean, home to the descendants of humans who were transformed into monstrous Fish People by mysterious entities centuries in the past.
    • Minifera, located even deeper than Ahmas, is lit by tiny, bioluminescent swimming creatures. It's home to the naiadans, an aquatic race whose individuals are made up of thousands of tiny creatures called dyremmi.
    • Morenel is a city on the abyssal plain inexplicably inhabited by humans, who have been living there longer than any surface-based human civilization has been around.
    • Onisteles is a colossal sea sponge that was colonized by an aquatic race called the glanae. The skin flakes the glanae shed feed the sponge, which in turn provides them with a home in a symbiotic relationship. What the glanae don't know is that Onisteles is in a similar relationship with a species of predatory animals called the ebons, where the predators protect the city from certain sponge-eating slugs... in exchange for Onisteles occasionally spitting out glanae to feed the ebons.
  • 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.
  • Transhuman Space 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 Warhammer 40,000.

  • Mahri Nui in BIONICLE: a Matoran city that broke off the island it was built on and sank into the ocean. Luckily for the Matoran living there, they landed on an underwater field of airweed, and the release of oxygen not only saved them but let them build a massive air bubble around their city. They now have to continually harvest more airweed to maintain it.

    Video Games 
  • 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.
  • Aquaria has Mithalas City, which has long since been completely ruined after a Path of Inspiration corrupted its patron deity into a horrible monster. Guess what you end up fighting in the ruined cathedral.
  • Atlantis Underwater Tycoon: The main premise of the game is to build and maintain one.
  • BioShock: Rapture is a Diesel Punk and Bio Punk city that's completely underwater, save for a lighthouse that contains a bathysphere to bring people down from the surface. Notably, the game addresses the massive load of engineering problems that comes with building a city underwater: Rapture is constantly leaking, parts exposed to the sea have a tendency to freeze over, and since most of the population is insane after New Year's 1960, leaving little in the way of a maintenance staff, by the sequel stretches of the city have outright collapsed under the water pressure.
  • Heretic's Domes of D'sparil sit under the sea, according to the image seen after completing the second episode.
  • Kirby: Both Kirby's Return to Dream Land and Kirby: Planet Robobot have underwater cities as background elements for their Under the Sea levels. The former's Onion Ocean has Atlantis-like buildings, while the latter's Overload Ocean is more like a modern Skyscraper City. They notably seem to be fully inhabited, since the buildings in both cities are well lit.
  • Mass Effect: Kahje, the homeworld of the aquatic hanar, is covered by water on 90% of its surface and features impressive domed cities, which they originally built for the drell after the hanar rescued most of the species from their dying homeworld, two centuries previously.
  • Sentinel: Descendants In Time has Goda, which was known for its underwater gardens and light and sounds.
  • Starbound: The Hylotl live in these, and it looks awesome.
  • Sunless Sea: There are several populated cities beneath the Unterzee that you can visit once you get the Zubmariner expansion. Most have their own unique peculiarities — Hideaway is built on the shell of a colossal hermit crab, Dahut is populated by Drownies and has water that can be breathed like air, Wrack is built out of sunken ships and home to wreckers, Nook is tucked into the maw of... something huge and lamprey-like, and Anthe is built into a crystal formation and home to people who seek to become more crystalline themselves.
  • Team Fortress 2: In the supplementary material, the entire country of New Zealand moved to an underwater dome.
  • Twisted Wonderland: Merfolk have an active civilization under the sea. From what we see of it, they have a large, architecturally grand arts museum.
  • Undertow (Chair Entertainment): With most landmasses gone due to mass flooding, humanity now survives by living in enclosed facilities along the ocean floor, as do the Nemonians, but the latter presumably did so long before the calamity given who their leader is.

  • Girl Genius: In the past, a cabal of Sparks rebelled against Her Undying Majesty; the fallout of the civil war caused the whole of Great Britain to start sinking for reasons no one really understands, but Londinium has survived under a series of stained-glass domes on the seafloor, connected to the surface world by tall spires that rise above the water and allow ships and dirigibles to dock.
  • Question Duck: One character claims to have been to an underwater city home to fish and dolphin people and to mermaids, which he helped defend against evil seals.
  • Zukahnaut's protagonist finds himself first imprisoned in, then ruling over, an undersea kingdom in a story where he swaps bodies with its leader.

    Western Animation 
  • The Futurama episode "The Deep South" features the Lost City of Atlanta — a joke on Atlantis, of course — which was turned into a City on the Water to attract more tourism, but became overloaded with buildings and construction and sank. The citizens who stayed behind ended up evolving into mermaids and mermen by the 3000s, thanks to the caffeine from the Coca-Cola plant (somehow) speeding up their evolution.
  • Jabberjaw takes place in a future with a number of underwater cities where the Neptunes perform before stumbling on some misadventure.
  • King has Bubble Town, the capital of the nation of Undersea, ruled over by the despotic Cousin Tess.
  • The Little Mermaid (1992): In addition to Atlantica, there is also Eel-Ectric City — a metropolis that's "so hopping it's always bopping".
  • Samurai Jack: The episode "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 City on the Water instead, but Aku banished it beneath the ocean to where it is now. It returns to the surface by the end of the episode.
  • According to the opening credits of Sealab 2020:
    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.
  • Sealab 2021 is a parody of the original Sealab 2020 in which nearly everyone working in the undersea city is some combination of stupid or crazy.
  • SpongeBob SquarePants is set in the underwater city of Bikini Bottom.

    Real Life 
  • While not entire cities, there are several hotels around the world that offer underwater rooms and suites.
    • Jules' Undersea Lodge in Key Largo, Florida is actually built out of an old research station that's completely underwater and can only be accessed by certified SCUBA divers.
    • In the Maldives, you can find a hotel containing rooms that allows you to see the Indian Ocean underwater.


Video Example(s):


Otoh Gunga

Jar Jar Binks leads Qui-Gon and Obi-Wan to the underwater city of Otoh Gunga.

How well does it match the trope?

5 (7 votes)

Example of:

Main / UnderwaterCity

Media sources: