%% Image selected per Image Pickin' thread: http://tvtropes.org/pmwiki/posts.php?discussion=1447706228078092100
%% Please do not replace or remove without starting a new thread.
[[quoteright:350:[[Series/StargateAtlantis http://static.tvtropes.org/pmwiki/pub/images/stargate_atlantis.jpg]]]]

A fairly common feature in near-future works is cities built on artificial islands in the middle of the ocean. Often they are built to alleviate overcrowding on land, especially when GlobalWarming causes sea levels to rise and envelop coastal cities, but just as often they are sites for {{Mega Corp}}s to do things that may or may not exactly be "legal" in most conventional nations.

Related to UnderwaterCity, which is when the colony is underwater instead of on it. Likely to also be a CityOfCanals.



[[folder: Anime & Manga ]]

* In ''Anime/DaphneInTheBrilliantBlue'', the setting is a series of connected cities on water due to a cataclysmic event that flooded the world.
* Franchise/GhostInTheShell:
** ''[[Manga/GhostInTheShell Ghost in the Shell: Man-Machine Interface]]'' (the manga) features Poseidon Industrial's artificial island city, where Motoko Aramaki's real body is typically stored.
** [[Anime/GhostInTheShell The second film]] has an android manufacturer that bases its factory on a ship [[spoiler:because they're dubbing the ghosts of young girls into their robots]].
* The conclusion of the Enies Lobby arc in ''Manga/OnePiece'' shows turning the CityOfCanals Water Seven into this is mayor and shipwright Iceburg's next big project.
* Neo Venezia in ''{{Anime/ARIA}}'', naturally, since it's a replica of Venice.
* The ''Anime/PsychoPass'' movie is set to take place primarily on a floating city owned by a Southeast Asian government in the Pacific called Shamballa.
* ''LightNovel/TheAsteriskWar'': Rikka, the series' main setting, is an artificial island-city based on a crater-lake in North Kanto.


[[folder: Film ]]

* In ''Film/{{Waterworld}}'', since all known land has been covered by water most people live in "atolls" made from scrap metal. As well as traders who live on boats and the "smokers" who are based on the Exxon Valdez.
* In ''Franchise/StarWars'', the populace of the water-world Mon Calamari live in giant floating cities. One half is above water for the Mon Cals and air-breathing visitors, one half underwater and flooded for the Quarren.
* San Angel from ''WesternAnimation/TheBookOfLife'' sits in the middle of a lake.


[[folder: Literature ]]

* Creator/DavidBrin's novel ''Literature/{{Existence}}'' has artificial islands popping up as sea levels rise. However most of them are resorts for the super-rich or havens for questionably legal biotech experiments. China has a "shoresteading" program for desperate people to try and make the upper levels of flooded mansions in what used to be Shanghai liveable.
* Creator/GordonRDickson's ''Home From the Shore''
* Creator/NealStephenson's ''Literature/SnowCrash'' has "Rife's Raft", a gigantic, cobbled-together collection of floating garbage in the Pacific Ocean inhabited by huge numbers of refugees, mostly from Asia.
* Creator/DavidDrake's ''Literature/TheLordOfTheIsles'' series includes a vignette in the first book in which Sharina, Nonus, and some useless nobles spend a few days on the Houseboats of the Sea People. They spend their entire lives at sea and live in large structures crafted largely from whale.
* ''Literature/NineteenEightyFour'' repeatedly mentions military installations called "floating fortresses" that are apparently under construction, which dwarf the ordinary battleships that were their inspiration -- but never explains what they are.
* In ''[[Literature/{{Gor}} Raiders of Gor]]'' we meet the Caste of Rencers, who live in a delta connecting a great river and the sea, gathering rence[[note]]a multi-purpose plant used for making paper, rope, utensils, cloth, and food[[/note]] for trade. They live in small villages built on floating rafts of rence. As the rence rots away underwater they weave new layers on top.
* The Skeezers in ''[[Literature/LandOfOz Glinda of Oz]]'' live in a [[DomedHometown city]] suspended over the middle of a lake. In times of danger they can magically submerge the entire city for protection, turning it into an UnderwaterCity.
* The pirate city of Armada in ''Literature/TheScar'' takes this trope UpToEleven, being built of thousands of ships, large and small, of every conceivable design roped together en masse.
* ''Literature/SaturnsRace'' takes place on an island grown from accreted sea chemicals ('seament').
* Thule from ''Literature/ArcticRising'' is a collection of ships and oil platforms attached to the last few bits of Arctic sea ice. Later, several of them decide to go their own way.
* In Creator/MikhailAkhmanov's ''Literature/ArrivalsFromTheDark'', between the second the third novels (roughly a 150-year gap), a new nation has sprung up on Earth called the Pacific Aquatoria, made up of privately-owned floating islands. Sergey Valdez, the protagonist of the third novel, is from one such island, owned by the Valdez family, but mortgaged to the bank due to the high costs of living at sea.
* In ''Literature/TheHobbit'', Esgaroth, or Lake-Town, is built on a series of wooden platforms in the middle of the Long Lake, ostensibly as protection from the local fire-breathing dragon.
* In ''Literature/Magic20'', the Sunken City of {{Atlantis}} is a gleaming reflective bowl that stands on pillars in the Mediterranean. It's explained that "sunken" does not mean UnderwaterCity in this case but more of an architectural style, like in a "sunken apartment". The outer shell of the city is pure solid diamond created on a molecular level with a macro (similar to a MatterReplicator but with programming code). Inside, the city has buildings all over the sloping walls with one-way windows through the "floor". FloatingPlatforms (also diamond) provide transportation across the city. Plumbing is handled by teleporting waste into orbit, resulting in a lot of shooting stars. The city is ruled by a triumvirate: the President (the sole elected post), Brit the Elder (the builder of the city), and Brit the Younger (Brit the Elder's [[TimeTravel younger self]]). Atlantis is a haven for female time travelers and the largest time traveler colony, as most of history [[BurnTheWitch wasn't very kind to women with magic]].


[[folder: Live Action TV ]]

* Atlantis, from ''Series/StargateAtlantis'' (in addition to being capable of becoming an UnderwaterCity should the need arise).


[[folder: Tabletop RPG ]]

* Classic ''TabletopGame/{{Traveller}}'' supplement ''The Traveller Adventure''. The planet Heguz is an [[SingleBiomePlanet Ocean Planet]]. It has had two colonies, both set up on large floating bases. Both colonies mysteriously disappeared without a trace.
* ''TabletopGame/{{Shadowrun}}'': Proteus Corp built a number of "arkoblocks" (floating arcologies) off the coast of Japan.
* One of the TabletopGame/{{Mystara}} modules for Basic/Expert/etc TabletopGame/DungeonsAndDragons features a floating city built on giant wooden platforms, kept above water by an enchanted idol that makes everything linked to it unsinkable.


[[folder: Video Games ]]

* A major gameplay element of ''VideoGame/SidMeiersAlphaCentauri'', as any faction can create sea based settlements as well as the standard land based ones, in contrast to the VideoGame/{{Civilization}} series where only land based cities are permitted. The Nautilus Pirates faction starts the game with such a settlement and can create an ocean empire faster than the others.
** The Rising Tide expansion pack for its SpiritualSuccessor, ''VideoGame/CivilizationBeyondEarth'', also allows players to build cities on ocean tiles. Ocean cities work very differently to land-based cities, with increased production rates for naval units and certain buildings, while facing other challenges, such as Kraken attacks and obstructive Hydra-coral growths. A new Sponsor, the very British/Scandinavian-flavoured North Sea Alliance, gives a number of bonuses to oceanic cities. According to the fluff, the founder of NSA is famous for pioneering the concept back on Earth with the so-called [=ARCs=], one of which he personally piloted to an island nation in danger of flooding and handed it over to the locals, earning himself international fame. Aquatic cities are unable to expand borders by accumulating culture (buying hexes with cash still works) but can build a recurring project that moves the city one hex upon completion, which expands borders. There is even an achievement for crushing an enemy unit with a city (difficult to do, since everyone can see the warning "arrow" coming from the city towards a particular tile). This way, aquatic cities can act as mobile bases for an invasion and an impromptu aircraft carrier.
* Frequent in RealTimeStrategy games that involve naval combat (most ''VideoGame/CommandAndConquer'' titles, for example): The ship-building structures are constructed directly at sea.
** Then there's the Black Tortoise from ''VideoGame/CommandAndConquerRedAlert3'', a huge floating fortress. Its also possible to make base in water, certain structures such as refinery's, power plants, and airbase can be built on water.
* ''VideoGame/{{Brink}}'' is set aboard The Ark, an experimental floating colony designed to be completely self sufficient.
* The Mechanical Age in ''VideoGame/{{Myst}}'' once was this, according to Atrus' account. The city, surrounded by three tall hills, [[SunkenCity sank]] when pirates destroyed its foundations, but he installed a fortress on top of it for the survivors to fight back with.
* ''VideoGame/KnightsOfTheOldRepublic'' has the planet of Manaan with the native water-breathing Selkath, which is covered entirely with water except for Ahto City, which is built on the surface of the ocean to accommodate visitors.
* In ''VideoGame/FinalFantasyX'', during the Shoopuf ride you learn about the city built over the ocean, which was built just because it could be. Needless to say, it got destroyed by Sin and sank to the bottom.
* ''VideoGame/ResidentEvilRevelations'': Terragrigia
* ''VideoGame/{{Syndicate}}'' (2012) has the city of La Ballena, which is owned by the Caymen Global syndicate.
* ''[[VideoGame/TearsToTiara2 Tears to Tiara 2]]'' has Tartetos, an AdvancedAncientAcropolis that combines aspects of {{Atlantis}} and [[UsefulNotes/PreColumbianCivilizations Tenochtitlan]].


[[folder: Webcomics ]]

* ''Webcomic/{{SSDD}}'' has the Britannia, a massive ship built on an iceberg that England's wealthy fled to when the Anarchists took over.
* In ''Webcomic/TheKennyChronicles'' Tarnekis, genetically engineered [[PettingZooPeople human-animal hybrids]] are largely forced to live on converted cruise ships. The sequel series, ''Ferrets vs. Lemmings'' takes place on an artificial island.
* In ''Webcomic/{{Homestuck}}'', there are a number of these (although we only see the one) in the future of Alpha Timeline Earth after the Condesce floods the planet, where Roxy and the timeline's Exile population live. Unlike the shiny high-tech version of this trope you usually see in science fiction, these are ugly blocks of prefab housing stated to be basically floating slums, since the well-being of her subjects isn't terribly high on the Condesce's list of priorities.
* In ''Webcomic/SchlockMercenary'' the capital of the United Nations of Sol is Dom Atlantis, a megalopolis of some 4 billion situated in the North Atlantic.


[[folder: Western Animation ]]

* In ''[[ComicBook/XenozoicTales Cadillacs and Dinosaurs]]'', the Remains of New York became a floating city called The City In the Sea.
* ''WesternAnimation/AvatarTheLastAirbender'': In the first season, the Fire Nation has a TailorMadePrison for earthbenders: a giant offshore platform built entirely out of metal (metalbending wouldn't be discovered for another season). One of the reasons TheMovie is so reviled is that it replaces the platform with a quarry, making the earthbenders' plight less "nothing to help us escape" and more "we can't be bothered to escape". ''WesternAnimation/TheLegendOfKorra'' has a similar situation with Ghazan's prison, out at sea and made entirely of wood (Ghazan isn't a metalbender, but they're known to exist by then) and without a speck of dirt anywhere. As we find out during his escape, Ghazan is a ''lavabender'', and just having a few pebbles on hand is enough for him to create a buzzsaw out of lava.
* ''WesternAnimation/TheMarvelousMisadventuresOfFlapjack'' has Stormalong Harbor, a rickety island made of wooden planks and piles driven into the seafloor. The harbor is [[LayeredMetropolis divided]] into "Upper" (where the rich live) and "Lower" (where the rest live) Stormalong. Despite being basically a huge harbor people live on, it has a functional plumbing system along with a trolley and enough support to hold up entire manors for the rich (the richest man in Stormalong has a massive one with a lawn, gardens, and fountains).


[[folder: Real Life ]]

* Certain groups such as [[http://www.seasteading.org/ The Seasteading Institute]] and [[http://www.blueseed.co/ Project Blueseed]] intend to do this in real life.
* The unrecognized micronation [[http://en.wikipedia.org/wiki/Principality_of_Sealand Sealand]] is based on one of the [[http://en.wikipedia.org/wiki/Maunsell_Sea_Forts#Maunsell_sea_forts Maunsell Sea Forts]] built during WWII.
* Frequently seen in nations with sea access and not enough space for new buildings (Japan, Singapore, etc.) as well as countries with an influx of wealthy tourists and investors (Dubai, Bahrain...). In fact, several airports (such as Kansai International in Osaka) have been built in harbors by using landfill (as in, the kind made from rocks and dirt, not the kind made from garbage) to create artificial islands big enough to operate major airports on. One major challenge in designing these airports is that the weight of the airport itself (buildings, planes, equipment, and of course miles of thick paved runway surfaces) causes the island to sink further into the water.
* UsefulNotes/{{Venice}}, although it's not in open sea, is probably the best known example we have today.
* Tenochtitlan, capital city of the Aztec civilization, was mostly built of "floating gardens" constructed around islands in a large lake. What is left of the city is located in the middle of modern-day Mexico City.