Underwater City

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."
Tales of Future Past

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. Usually though it's a modern attempt at colonizing the ocean floor, or a villain's secret lair.

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.

Compare Underground City.


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    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.
  • 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.
  • 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.

  • In 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.
  • Both Marvel Comics and DC Comics have versions of Atlantis, although in both cases Atlantis is a big place with multiple cities.
  • There was an arc in Aquaman where half of San Diego slid into the sea following a massive earthquake... and those who survived it instantly adapted to underwater conditions.




     Live Action TV 
  • The Man From Atlantis episode "Crystal Water, Sudden Death".
  • In the first episodes of Stargate Atlantis, 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.
  • 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.
  • 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.
  • In Star Trek: The Next Generation, 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.

    Tabletop Games 
  • 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 New Horizon, Aquilon's Reach has multiple underwater cities, as well as some atop glaciers. Unsurprisingly, they also boast the best navy in game.
  • See the Shadowrun, 2nd Edition supplement Portfolio of a Dragon: Dunkelzhan's Secrets; in his will Dunkelzhan left a bequest of 5 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.


     Video Games  
  • Rapture from Bioshock, which gets extra points for being a Diesel Punk and Bio Punk city as well.
  • The Dome of D'sparil from the last level of Heretic.
  • The Call To Power series has sea cities.
  • Area J from Mega Man ZX.
  • 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.
  • In Mass Effect, it's mentioned that Kahje, the homeworld of the aquatic Hanar has 90% of the surface covered by water and features impressive domed cities, originally built them for the Drell after the Hanar rescued most of their species from their dying homeworld, two centuries previously.
  • The main premise of Atlantis Underwater Tycoon is to build and maintain one.

    Web Comics 

    Web Original 
  • In The Gamers Alliance, Adlivun is a thriving underwater city populated by merfolk known as merrows.

     Western Animation 
  • Futurama featured the Lost City of Atlanta.
  • 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.
  • Sealab 2021
    • ... not to mention the other Sealab featured on Centurions .
  • The Superjail episode "Superbar".
  • Jabberjaw.
  • Jonny Quest The Real Adventures episode "Undersea Urgency".
  • Atlantica from The Little Mermaid.
  • They visited Atlantis on The Fairly OddParents. Also, Clevelantis.
  • The main premise of Atlantis The Lost Empire.
  • King had Bubble Town, the capital of the nation of Undersea, ruled over by the despotic Cousin Tess.
  • The Adventures of Super Mario Bros. 3 had one in the episode "The Ugly Mermaid". It was a bizarre case in that the city had domes with air in them, despite the merfolks not being able to breathe air.

     Real Life