An otherwise-normal place that's floating in the sky, often for no adequately-explored reason.
This is an extremely common trope in fantasy and video games. Nothing says "exotic" like a city floating in the sky. Outside of scifi settings, there's often no real effort to justify or Hand Wave it beyond saying A Wizard Did It and hoping that the Rule of Cool will carry the day. Or never mentioning it at all.
One thing's for sure, though: If you've got a Floating Continent, it's significant. There's no chance that it's just some random village. Even if it's not The Very Definitely Final Dungeon, something important is definitely going to happen there. These places tend to have a higher-than-normal failure rate as a result of this, often becoming more of a Falling Continent.
Waterfalls are often expected to fall from the continent. Even if there's an explanation for how the place stays in the air in the first place, how they can possibly not run out of water is pretty much never explored. (While it's not that hard, as long as there is some sort of world below and the continent doesn't permanently float above the clouds it can get its water the same way any mountain range does: rain.)
Strangely enough, many such places go unnoticed by the common man, even though they should be perfectly obvious floating there in the sky. Sometimes they're cloaked by clouds, mist, or Applied Phlebotinum, but other times... well, you have to wonder how people can be so sure that the Floating Continent is mythical if they've heard of it at all.
The Ur Example is the original Cloudcuckooland, from Aristophanes' The Birds, but the Trope Codifier is the City of Laputa, from Jonathan Swift's Gulliver's Travels. Swift also originated the Colony Drop: Laputa maintained control of its groundbound colonies by landing on any rebellious population centers, crushing them beneath its armored underbelly. The trope was popularized in modern popular culture by Hayao Miyazaki's Castle in the Sky. The Trope Namer is the Floating Continent orbiting Jupiter in Star Blazers / Space Battleship Yamato.
If some cataclysm has resulted in the entire planet being broken up into a collection of floating continents, that's Shattered World.
If there is no landmass under these continents, then it's World in the Sky.
Ominous Floating Castle is its own trope.
Eponymous Laputa: Castle in the Sky, released as Castle in the Sky in some markets (Especially because in Spanish, "la puta" means "the whore". In Spain, e.g., "Laputa" was changed to "Lapuntu"; in the US and Mexico "Laputa" was simply omitted).
Tower of God has several on a few of the Tower's floors, most notably the Evankell testing center, Repellista's castle, the Sea of Clouds on the 25th and the Winged Cities of the 21st Floor.
Edolas from the Anima arc of Fairy Tail had an assortment of floating islands, including the one carrying the Eksheeds' homeland of Exteria, and another that the King used to store the Magnolia La'cryma.
Most of the .hack series of animes and games have floating rocks, islands and the like. Makes sense, seeing most of the animes and all of the games are set in a fictional MMORPG called "The World".
In the manga version of Chrono Crusade, the Sinner's home is a small floating town called Eden. It exists because (1) demons are actually aliens, who came to Earth on a fish-like spaceship — so the Sinners have access to technology that would allow for that sort of thing and (2) the Sinners are on the run and need to be in hiding, so a home base that's removed from people is probably a better idea than forming a colony somewhere on Earth.
The entire plot point of Edens Bowy is about two floating continents, Yulgaha (or Eurgoha), and Yanuess. The people below regard them as gods, and some places actively do something for them, like providing water, or becoming an industrial place. Eurgoha is the larger, having high-tech cybernetic technology but is somewhat high-strung, while the smaller Yanuess is industrialized to the point of constant pollution (plus ruled by a cat-eared woman). Eurgoha and Yanuess eventually collide together, and a good chunk of Eurgoha falls. Yanuess is more or less intact, but Eurgoha is messed up, in a whole lot of ways.
The Neo Nation colonies of G Gundam are a really odd example - not only are they space colonies, but they actually seem to be gigantic hunks of Earth which lifted off the planet and floated into space. Keeping with the show's Refuge in Audacity, most of the colonies (except Japan) are unusual shapes - Neo America is a star, while Neo Mexico is a giant sombrero.
A floating island of devious monkeys appears in Kyouran Kazoku Nikki. This one does have a reason for the hovering — Levistone, the same material that powers Hyouka, one of the main characters.
In Mahou Sensei Negima!!, Magicus Mundus had one of these... until Asuna's Anti-Magic caused most of it to crash. All that left now are small clumps of floating debris.
In One Piece, an entire saga revolves around how to get onto one of these, where different types of clouds serve as both land and sea (called both "Skypiea" and "Sky Island") and the Straw Hats' adventures on it.
In Sonic the Hedgehog: The Movie, seemingly all of society lives on floating islands (as opposed to the games, where there's just one). Heavy cloud cover makes the otherwise perfectly habitable regular ground more or less abandoned (and earns it the name "The Land of Darkness" to boot). The only ones who dwell there are Robotnik, who implicitly doesn't care that it's so gloomy so long as he has the place to himself, and his robots, who obviously don't care that it's so dark.
Also, there's no threat of these continents falling to the ground — instead, the threat is that they'll be flung out into space, as the continents all join at massive glaciers that functionally anchor them to the planet's surface. If it were to be destroyed, the combination of the planet's rotation and their own anti-gravity would cause them to hurtle out of orbit, being torn apart in the process.
The Trope Namer is Star Blazers / Uchuu Senkan Yamato, in which one of these exists in the atmosphere of Jupiter, until the crew (unintentionally) obliterates it the first time they use the Wave Motion Gun. They had no idea how powerful the thing would be, and were expecting to only hit the enemy base on the continent. This may also count as World in the Sky, Jupiter being a gas giant.
Vash in Trigun got his coat, artificial arm and third gun from a massive colony of SEEDS that never hit the ground, and so remain peacefully isolated from the Crapsack World, comfortable with their future tech. When Vash goes back for repairs and upgrades, naturally trouble follows him.
Magic Knight Rayearth: The shrine of the air-elemental Mashin, Windam, is located on a solitary airborne mountain.
Space Battleship Yamato 2199 humanity finds one the size of Australia floating on Jupiter of all places, populated with lush verdant forests that are also poisonous to humans. The Gamilons placed it there in order to speed up the terraforming of Earth once humanity had been destroyed, in kind humanity destroys the whole continent with it's prototype Wave Motion Gun.
The sadly short-lived CrossGen comic Meridian features floating islands over a poisoned and barely-livable surface. They are held aloft by a substance called "floatstone" woven into the rock (and floating ships to travel between them, made with special floating wood). There was even a completely artificial island. Cities had to be careful about adding too much mass, though, or collect a type of floating coal to stay up. One such city ends up dropping.
Superbia, the home of the International Ultramarine Corps in the DC Universe, is a city that floats over the remains of Montevideo.
Within the pages of Cable & Deadpool, Cable converts his former base into a floating island.
Before the travesty of Amazons Attack, Themyscera, i.e. amazon island, was displayed as having multiple small islands that floated in midair, WITH WATERFALLS. This was often handwaved as being either magic, high tech, or a combo of both.
Supergirl's home town of Argo City, which survived the destruction of Krypton for a while as a floating planet chunk.
The Mighty Thor's home of Asgard was always portrayed as a great land mass floating in extradimensional space.
Between 2007 and 2010, it was a great land mass floating over Broxton, Oklahoma.
In the Marvel 2099Cross Over "Fall of the Hammer", "Asgard" was a floating city controlled by Alchemax, with security provided by a mind-controlled fake-Thor.
In Scott Pilgrim and the Infinite Sadness, this is apparently where Ramona went to college, the University of Carolina in the Sky.
In some continuities, the cities of Thanagar float.
The Bazaar in Romance and the Fate of Equestria serves as the centerpiece for a fairly large portion of the story. The floating city travels the world, returning to Equestria every few years, and as its name suggests, is predominantly a marketplace.
Mongo in Flash Gordon was somewhat like this, especially in the case of the Hawkmen's home, and possibly Aboria as well.
Avatar is set on a world full of such floating islands, held up by the Meissner effect - Unobtainium is a high-temperature superconductor which does this without needing to be well below freezing like ones currently available on Earth.
Cloud City in Star Wars The Empire Strikes Back is a huge floating city situated high in the skies of planet Bespin, which is otherwise an inhospitable gas giant, justifying the trope here.
In The Player of Games by Iain M. Banks, one character, whose job is to build Orbitals (artificial ring-shaped worlds), talks about making Floating Continents because she thinks that orbitals are too mundane, having fairly standard planetary ecosystems and landforms. She was also a big fan of volcanoes.
In the same universe, there are the inhabitants of the Airspheres. The smallest independently sentient species found in the airspheres are floating creatures the size of large buildings, and the largest (referred to as Gigalithine Lenticular Entities) are effectively sentient floating countries.
Various flying castles in Steven Brust's Dragaera novels. All of them fell out of the sky during the Interregnum, since they depended on sorcery powered by the then-unavailable Imperial Orb, but Castle Black was later raised again.
In Steven Erikson's first book of Malazan Book of the Fallen, Gardens of the Moon, the armies of the Malazan empire besieging the city of Pale face a flying fortress called Moon's Spawn under the command of a powerful sorcerer, Anomander Rake.
John Hodgman's The Areas of My Expertise talks about a 51st U.S. state, Hohoq, a plateau surrounded by clouds that floats mysteriously around the United States.
The eponymous Kingdom beyond the Waves by Stephen Hunt is one of these, though the previous book established that great chunks of land do this often in floatquakes due to uncontrolled magic.
Larry Niven's Ringworld includes floating buildings, most of which fell when bacteria ate their wiring.
One of the Light Novels of Vampire Hunter D takes place in a floating town, and at one had to deal with a floating pirate fortress. The town ends up being overrun with vampires caused by a failed experiment, and the residents of the pirates were long dead run by an AI.
Paul Stewart's The Edge Chronicles has the floating city of Sanctaphrax, which is built on a floating rock. Unusually, the main problem isn't keeping it up, but rather keeping it down, with the help of one gigantic chain and a chest full of stormphrax.
The original Laputa (accept no substitute!) appears in Gulliver's Travels, and is a magnetically floating island populated by Strawman scientists and philosophers with no common sense.
The City in the Sky from the War of Powers fantasy novels by Robert E. Vardeman and Victor Milan.
Magnus has Dragylon the Imperial Fortress: a massive, invisible, sun-sphere and headquarters of Lucifer.
In Wen Spencer's Endless Blue, all sorts of islands float. When someone tells Mikhail that his warp drive won't work, this is what convinces him: a place with floating islands is not obeying normal physics.
In Perelandra by C. S. Lewis, all the continents of Venus/Perelandra float on water except one. There is one divine rule on Perelandra: never sleep on the fixed continent.
The protagonist of the bizarre story Tower of Babylon by Ted Chiang is working on the archetypal Tower of Babel — which is literally built to reach the sky, a flat plate of rock, above which heaven is presumed to exist. The builders climb past stars of heated rock and tunnel into the sky, but unleash a local flood by drilling into a chamber full of water. The protagonist continues upward and emerges back on Earth, more or less where he started, because space is tightly folded — Earth is above itself.
In Alexander Bushkov's Svarog series of novels, the swashbuckling-and-sorcery world of Talar has these flying islands, populated by the local uber race of wizard-nobles.
Animorphs had Ket, part of their Expanded Universe, which had the planet's sentient species living on and maintaining their floating continents. The entire species worked to fly their continents through the sky, mainly because the planet surface is highly toxic.
The Ketran death sentence is sending the offender to the surface, away from the continents. Because the Ketrans can't really fly, they glide, once they fall below the continents, they're dead.
The human inhabitants of Turquoise, an ocean world in one of the stories in Alastair Reynolds' Diamond Dogs, Turquoise Days (part of the Revelation Space universe) live in "snowflake cities", giant vacuum-buoyed city sized airships. Boats are not an option, as the alien Juggler biomass that fills the oceans breaks down nonliving materials at rates far too quick to repair.
The Three Worlds, setting of the Books of the Raksura, are littered with floating islands, buoyed up by the lumps of magical rock found within. These rocks retain their properties when removed from the islands; one race of groundlings uses them to power flying ships.
Isaac Asimov's short story Shah Guido G concerns the existence and eventual destruction of a levitated city.
Several of Vladimir Vasilyev's novels are set on a world whose surface is uninhabitable. Instead, people live on giant leaves that float on the strong air currents. Some of the stories deal with characters who find themselves on another leaf and are unable to return home, when the winds separate the leaves.
Averted with Atlantis in Scott Meyer's Spell or High Water. It's designed to look like it's floating above the sea. In fact, it actually stands on several very thick pillars that are highly reflective. Interestingly, the "sorceresses" could have made it float (levitation spells are fairly easy), but decided to avoid any problems that could cause. Of course, levitation works best on monolithic objects, and a city is anything but monolithic (although the main "bowl" on which the city stands is made of solid diamond).
The seemingly primitive Nox from Stargate SG-1 are revealed to have built a floating city in Season 1 of the series
And the Ancients also have a flying city... that travels through space.
The Animarium in Power Rangers Wild Force. This thing might as well have a yo-yo string on it during the course of the series, as it went up into the sky, crashed back down, and went back up again... of course, if Saban and Disney had managed to work things out, it would have managed to come back down for the next team-up episode...
The Sliders episode "Seasons Greedings" features a giant floating mall. People in there shopped, worked, lived there, shopped some more, and failed to work off their debt slavery (as opposed to Earth Prime, where the debt slaves are forced to find their own living quarters, too). If there's any structure which wastes this much energy just to make itself look spiffy, it just has to be a host body of a Starbucks.
The Firefly episode "Trash" features the crew staging a robbery on Bellerophon where ultra-wealthy citizens reside on their own private estates that float over an idyllic sea.
Roger Dean's album covers for the progressive rock band Yes are absolutely packed with these.
The videos for "Feel Good Inc" and "El Manańa" by Gorillaz feature Noodle on a floating island with a windmill.
Dungeons & Dragons settings frequently have more than a few floating continents or cities of various sizes.
The ancient empire Netheril from the Forgotten Realms had a host of magical floating cities. Most were destroyed 4,000 years "ago" when a power-hungry mage accidentally caused magic to stop functioning. A few survivors landed safely but never flew again. One escaped into the Plane of Shadow, to return thousands of years later and start refounding the Netherese Empire.
In 4th Edition, the magical structure of Faerun went completely bitchcakes when the god of magic got killed. As a result, there are zones of wild magic where large chunks of the landscape sits above the landscape.
In the Known World (or Mystara) setting, one of the sub-kingdoms of the magical Alphatian Empire consists entirely of floating islands. There's also a large number of floating landmasses in the worlds' hollow interior. Amusingly enough, during the metaplot the mainland of Alphatia is one of these, recreated after it sinks by the setting's gods as a literal Floating Continent.
Mystara also features the gnome-built (and mobile) Flying City of Serraine and its magic-powered biplanes.
The Dragonlance setting had a floating fortress, a relic of more powerful magics in antique times.
There were actually several flying citadels in Dragonlance, one of which got Mist-napped and is now a pocket domain in the Ravenloft setting.
Mt Metagalapa in Exalted, which began floating around at the same time as the foundation of the Realm. Savants theorize that the combination of Wyld Essence from a Fair Folk invasion and the aftereffects of firing the Realm Defence Grid screw it they have no sodding idea why it floats. This is because they don't realize the heart of the mountain is a Titan-class citadel from the First Age. Basically, we're talking an Ominous Floating Castle fitted with a city-destroying mile-wide Wave Motion Gun, forgotten for thousands of years, and encased in stone.
It also held Emrakul, The Aeons-Torn, a floating Eldritch Abomination the size of a mountain range. The plane of Zendikar, was, in fact, used as the can that kept it and the other titanically huge Eldrazi sealed, until a group of planeswalkers were manipulated into breaking said can and letting the Eldrazi free.
Eclipse Phase has these on Venus. Thanks to the incredible air pressure and the advent of super-light materials, humans managed to build enormous flying cities called aerostats in the upper atmosphere of Venus before the Fall.
In Disney Epic Mickey, the Cartoon Wasteland is basically a model of Disneyland sitting on a table in Yen Sid's tower. But to an observer actually inside the Wasteland, it seems to be a group of floating islands.
The Elder Scrolls III: Morrowind features a prison island floating over the capital city of Vivec. Originally, it was one of Nirn's moons but a Daedra ripped it from its orbit and dropped onto Vvardenfell. Vivec, the Physical God after whom the city was named, managed to stop its fall but he couldn't neutralize its momentum, so he more or less froze the moon in time. Early in the Fourth Age, Vivec dies as a result of the players actions in Morrowind, and the moon resumes its fall. A machine that Dunmer engineers build to keep it up is eventually destroyed, as well. The moon hurls to earth with the entire momentum from its orbital fall centuries ago and wipes out the city. The seismic shock causes the nearby supervolcano Red Mountain to erupt, killing everything still clinging to life on Vvardenfell. The moral of the story being: gravity is one mean mother.
The Trope Namer is the Floating Continent in Final Fantasy III. The first quarter or so of the game is spent on the Floating Continent without you even knowing it. It's almost as big as the world map when you're on it, but very small when you're on the world map.
Final Fantasy VI features an area with the same name. It averts the "unnoticed part", since the city below it gets shadowed and the people on the streets comment it.
As well as the Riverne peninsula, which is now a flying archipelago. When a giant explosion blew the peninsula into tiny bits and threw it into the air, it just simply never came back down.
The floating city of Bhujerba in Final Fantasy XII, which floats due to a high quantity of a minable magic crystal called 'magicite'. There are other floating landmasses ssen as background images, but Bhujerba is the only populated one.
Mt. Bur-Omisace, the Kiltias' sacred mountain, is surrounded by countless floating islands. Some are large enough to support man-made structures and shrines. They say that these islands are remnants of a Floating Continent which fell and broke apart long, long ago.
The moon-sized Cocoon in Final Fantasy XIII is unique in that, rather than being a flat strip of land with a definite surface and bottom, it is actually a miniature Dyson sphere, complete with its own "sun", the Fal'Cie (robot god) Phoenix.
Spelvia, the Floating City, in Final Fantasy: The 4 Heroes of Light. It's the home of the original Hero of Light, as well as the location of the Climax Boss which splits the first half of the story from the second. Its golems describe it alternately as "a fortress to conquer the world" or "a fortress to protect the world."
The Nazca Sky Gardens in Illusion of Gaia, which float above the huge drawings on the Nazca Plains.
Skies of Arcadia is set on a series of islands floating in midair, as befitting a game about PiratesIn Flying Ships. Like most JRPGs, however, the overall world map is shaped like a torus. It turns out that there is a contiguous ground underneath all the flying continents, but nobody yet had the technology to reach it due to pressure and wind issues.
Soltis, the lost Silver continent that rose from the planet's actual surface, is closer to the classic version of this trope, but it sinks again.
Skies of Arcadia also contains the following amusing statement (by one of the characters): "The world is a sphere. This means that the east is connected to the west, and the north is connected to the south."
Similarly, Japanese RPG duology Baten Kaitos is set on chunks of floating land that got that way due to a cataclysmic application of magic in a "War Between the Gods". However, it turns out they're floating above the surface of a normal planet of indeterminate shape from which they separated, and eventually float back down at the end of the first (chronologically second) game.
Baten Kaitos Origins, the prequel/sequel to the original Baten Kaitos has Tarazed, a flying fortress that completely pops out of one side of one of the floating continents and can blow up other floating continents.
The Sonic the Hedgehog series has several such examples of this trope throughout the years:
Bowser's castle occasionally does this in various Mario games.
Super Mario 64 had a lot of levels that floated in the middle of nowhere, with bottomless pits, but the standout example is Whomp's Fortress. Super Mario Galaxy seems to take after it with levels like Beach Bowl Galaxy, although justifying it in that it's in, well, space.
Mario Kart Super Circuit has Sky Garden, a garden track floating high in the sky.
Glitzville in Paper Mario: The Thousand-Year Door seems to be kept aloft by rockets, and is pretty much a tourist trap with a fighting arena. One character wants to build a sauna there, but apparently it's against the fire code for a floating island.
The Mana Fortress in Secret of Mana. Destroyed in the backstory. Floated again late in the game. And in the end, it was destroyed again.
The city state of Shevat in Xenogears. Also, Solaris.
While Solaris is definitely indeed located high in the sky, according to Perfect Works, it is 'anchored' by a massive pillar going all the way down to an island in the middle of the ocean, so it technically wasn't 'floating'.
The zone Nagrand has small islands floating high above the seemingly solid ground.
The Undead scourge use a fleet of floating necropolis citadels as bases, which acts as their town halls in Warcraft 3, and act as Dungeons, instanced or otherwise and cities in World of Warcraft.
With the Lich King expansion, the city of Dalaran was uprooted and now floats above the northern continent. But then again, considering who lives there...
Cataclysm introduced two instances that take place in the Skywall: Vortex Pinnacle and Throne of the Four Winds. While Skywall is presumably much larger than what was seen, they both qualify as being sky cities.
City of Heroes: The Mu have their city floating high in the sky, an island raised from the sea by their goddess Hequat to save her followers from destruction by the Orenbegans (Circle of Thorns). It can be accessed in some late-game CoV content.
The entirety of Cave Story takes place on (or more accurately inside) a floating island. Depending on the ending you get, it either falls from the sky or starts falling but stops.
It's an interesting case, because the nature of the place as a floating continent is kept hidden from the player for quite some time. The extensive cave network and the references to "The Surface" are pretty good at convincing you that the game is taking place underground. Turns out that the surface refers to below the island.
Doubly interesting in that, while the actual mechanics are more-or-less of the A Wizard Did It variety, the root causes of the island's floatation are very much a part of the game's plot. In fact, the truth of the matter seems to be a mystery to the island's denizens. The stated reason, while functionally true, is not inherently necessary.
Exire in Tales of Symphonia, the last place of solace for the oppressed half-elves. Oddly enough, it has no direct impact on the plot, serving only as a place where Raine confronts her mother, who has unfortunately gone insane after abandoning her and Genis, as well as the location of the bonus Summon Spirit Maxwell.
Nearly all the battlegrounds in Super Smash Bros.. are Floating Continents. The stage editor in Brawl doesn't even allow anything else. Also, there's an actual Floating Continent in The Subspace Emissary, as well as the labyrinth in the 3DS iteration's "Smash Run" mode.
In Lunar: The Silver Star, all the mages lived in Vane, a floating city/school of magic. They crashed, but ended up relatively intact. Made one heck of a crater, though.
Ogre Battle has the sky islands, which mostly function as bonus stages.
Stratosphere has flying fortresses that you control directly. The game is divided in between a building interface, where you get to build the fortress of your dreams, and the actual action, where you control the fortress as if it was a ship and blast enemy fortresses out of the sky while you try to minimize damage to yours. Everything is explained away with the presence of magical minerals of some sort.
Project Nomads lets you control the single buildings on your floating fortress, and you can tell the fortress to move between waypoints, but you cannot control it directly. You can also use your jetpack (or your legs, if you have time to waste) to get off your fortress and visit other large masses of floating land, some much bigger than yours.
In Heroes of Might and Magic V, the Academy faction's towns are all of this type. However, it only serves an aesthetic purpose as these cities can be sieged and captured by a non-flying army perfectly well - they land to meet the attackers instead of throwing something heavy on them, or, better still, landing ON them.
It should be noted that the Academy cities seen before the Tribes of the East does not actually fly, even though the town screen quite heavily suggests this - the first truly flying city seen in the series is encountered in Zehir's Tribes of the East-campaign, and serves the role as a campaign-specific game mechanic wherein Zehir can land the city in tactical locations large enough to hold the city for the price of a sum of his experience, thus allowing him some manner of logistical flexibility.
This goes back to Might and Magic IV with the Clouds of Xeen, which are stationary cloud banks connected to the world by the towers. They're not solid enough to support people, but levitation magic can support you over the clouds. In the game's counterpart, Darkside of Xeen, the area above the towers is primarily connected by skyroads, but there's also the city of Olympus, which is situated on a true Floating Continent.
Golden Sun had frequent mentions of a floating continent, and you could even visit the location it was in before it took to the sky, yet you never got to go there. Hopefully it will be touched upon when they finally get around to making Golden Sun 3.
Of course, the fact that there's an edge to the world that you could fall off of (if the game didn't prevent you from doing so, anyway), which will eat away at the world if power isn't restored to the four lighthouses, suggests that the world itself is a floating continent.
And we did not get to see the floating continent, just more hints. Of course, Felix and Sheba disappeared, and she's from there, so... # 4 anyone?
Zepp in Guilty Gear, though it is a country, not a continent.
The Emperor's Palace in Jade Empire is made of a special rock with magical properties that floats. The cutscene showing your approach is quite impressive.
The entire gameworld in Septerra Core is a concentric series of floating continents around the eponymous core. Having six layers of them takes it Up to Eleven.
The Legend of Zelda: Twilight Princess features The City in the Sky, a floating continent and the final regular dungeon in the game. It seems to float using massive fans/rotors on the bottom, and pretty much everywhere else.
Link's home in Skyward Sword is Skyloft, a group of islands floating in the sky above Hyrule. a goddess did it to ensure humanity would survive a war on the surface. Something of an inversion for Skyloft's residents, because they all consider hovering islands mundane; to them, the ground is an impossible mythical entity. Nonetheless, Skyloft does have The Very Definitely Final Dungeon, and said dungeon falls to earth after you complete it.
Also, there's the palace in the sky from The Minish Cap, which is a (very large) mansion floating in midair.
While rolling up a new universe in We Love Katamari, several floating islands appear somewhere above the ocean. Of course, they are just there to make it harder to run from the 1,000 Meter+ Octopus until you get big enough to roll the islands (Or the octopus) up.
Nearly every level in the first three Spyro the Dragon games was a floating continent.
The Lufia series has Doom Island, the floating island/castle where the Sinistrals resided.
In ToeJam & Earl, each level is a floating chunk of land. Falling off one lands you in the previous one, implying that they're arranged in a vertical stack.
For what it's worth, you do take an elevator to go from level to level. (Yeah, it's that kind of game.)
Numerous floating islands are also found in Ellenier chapter in Serious Sam 2.
The entirety of the Jumping Flash series of games has all it's levels based around this trope. This was usually explained by the plot, where the Big Bad tries to dismantle the world. Strangely, while all the levels in the third game, Robbit Mon Dieu, are implied to take place on the planet itself, the levels are still of the floating continent type. Why this is is never adequately explained.
Metroid Prime 3 has Skytown, a hemisphere-spanning system of flying buildings in the skies over Elysia. As Elysia is a gas giant, it makes perfect sense.
Luna Online takes place in Blueland, a Floating Continent unto itself. There is a lower world, but it's inhabited by demons and sealed apart from Blueland to keep them from causing trouble — although the seal has cracked, causing some problems.
There are multiple floating continents in the Mega Man X series, including Sigma's fortress, Sky Lagoon, and Giga City (although technically a collection of islands). The first two inevitably fell, especially Sky Lagoon which was deliberately dropped onto a city.
An unusual twist on the concept was a central theme of bizarre Namco arcade game Prop Cycle. The town of Solitaire becomes one of these after someone accidentally turns on some Lost Technology, and the player must leap astride the titular pedal-driven aircraft, fly back up there and somehow bring it safely back down to the ground before they run out of loo roll and incur ruinous cellphone roaming charges... or something like that, anyway.
In Heart of Darkness, there is what looks like an upside-down mountain floating above the world, where live the "Amigos." Weirdly, it has inverted gravity compared to the main land — if you fall from the mountain's edge, you go UP into the sky. If you reach the mountain's "top" (its bottom from a non-inverted viewpoint), then you're claimed back by the gravity of the earth and fall down.
The flying city of Caldoria is the home of temporal agent Gage Blackwood in the The Journeyman Project series.
The Ratchet & Clank Future saga has Stratus City in Tools of Destruction and the Valkyrie Citadel in A Crack in Time.
The third installment to the BioShock franchise, BioShock Infinite, has a floating city as the new setting, named Columbia. Created by the American government sometime in the late 1890's, Columbia was "designed to demonstrate to the world by example the founding democratic principles of the United States, the product of American ideals, endeavor and industry." Basically, it would fly all over the world and export American ideas to other parts of the world. Unfortunately, this equates to "a giant spaceship armed to the teeth and violently xenophobic", when Columbia tried to save American tourists during the Boxer Rebellion by firing on Chinese rioters. The American government did not take this well. Following the traditions of 'real' Americans, Columbia seceded and went off the grid, never to be seen again. Until the player character is sent there and finds everything has gone to Hell.
At first, everything seems...well, like Heaven. But after a few carnival games and some musical numbers, the city rears its ugly head; this is before 1945 - American-American Columbians are NAZIS. The jackpot for winning the lottery is the first pitch at an interracial couple. Every American in the city now blindly worships their new Neo-Christian religion with the city's mayor, Comstock, as a false Second Jesus. Fink Industries is THE Mega Corp. of Columbia, and it uses Non-Americans as practically slaves with paying jobs listed in a BIDDING WAR (bids uses time as a currency and bidding for the job means you have to complete it in less time for less pay). And the long-term goal of the city is to raise Comstock's daughter as a holy warlord and raze/conquer the world. And it happens in one alternate timeline. AND TAXES ARE NOW SET AT FIFTY FUCKING PERCENT - 50%!!! It gets so bad, that the underclasses rising up, devolving into anarchists, and completely obliterating the city is considered a GOOD THING.
Speaking of Pokémon, PokéPark Wii's final stage is Mew's home, the Sky Pavilion, an island floating peacefully above the park.
The (remains of?) the continent of Gracia in Lineage2 after the Zealots of Shilen used the Seeds of Destruction and Seed of Infinity to destroy and mutate nearly all life on the continent, turning nearly everything there undead. The only way to get around is by airship or turning into a flying creature.
Kyushu in Mystical Ninja Starring Goemon, where this trope is played straight. It becomes the final dungeon, and after you kick some ass, it becomes the Falling Continent, until it lands safely back in Japan.
Fly FF has a few of these, but they're mostly empty and seem to be mostly there to make the flying a bit cooler.
The second Knights of the Old Republic features "Citadel Station" that by its size qualifies as a floating continent, although it is an artificial construct and not so much floating over the planet as in orbit around it.
The climactic sequence of Neverwinter Nights Shadows of Undrentide takes place on an aforementioned Netherese floating city as it rises into the sky again.
The Dream World Fade in the Dragon Age setting features the so-called Black City (formerly Golden City of the Maker) floating ominously in the sky. According to the lore, it is seen from every point of the Fade (Euclidean geometry be damned) and it actually is from every Fade level in the games. On the other hand, it is completely unreachable by the player as of part two. Still, one DLC features a character strongly implies to have been to the Black City.
Terraria has floating islands, which contain a building with some rare items inside.
As with Minecraft, it is not hard to make your own: build a small wall, mine out all but the top, and the top will just float there. This can be important in "hard mode", when the Corruption and the Hallow begin to spread, since they will not spread through a thick enough air gap - so if they become or are completely surrounded by these, they are contained. Or just mine out below the spawn point, so that anyone joining the world or respawning starts off somewhere safe.
There used to be a planned dimension filled with these, known simply as the Sky Dimension. It made it as far as a terrain generator hidden in the 1.6 and 1.7 betas, and it was accessible through hacking until some time in 1.9 beta. It was then replaced with the End, a floating mass of white stone in an endless black void where the final boss is fought.
The popular Minecraft mod The Aether is exactly this. As opposed to the Nether, which is a dark empty space surrounded by land, the Aether is composed of bright and sunny landmasses surrounded by empty space in the sky. It also features new mobs, new soils/rocks, new items, and 3 boss encounters whom, even with all the right equipment (even weapon mods), will invoke a violent, hellish wrath upon you. The third boss, the Sun Spirit, even keeps the sun eternally locked at high noon, and uopn his defeat, day/night cycles will return to how they are down on the surface.
RuneScape's Clan Citadels are located on giant floating sky islands. They are the lost bastions of Armadyl, who is worshiped by the aviansie and is often aligned with the element of air. The clan citadels are also introduced by having large chuck of rocks falling from the sky.
One of the levels in Soulcaster II is set in the ruins of a flying city.
Kirby Air Ride's City Trial mode has a structure floating above the city called the Sky Garden, accessible via the volcano's launching pad.
The asuran race in Guild Wars and Guild Wars 2 build giant floating cubes and then live in them. That is explained by their use of magic and fear of living on the surface, rather than underneath as they used to. However, they apparently got inspired by all the chunks of earth floating above ground for no reason whatsoever.
The inhabitants of Megadom from Meteos live on huge chunks of rock that float atop the extremely dense atmosphere of their planet.
The Skyward kingdom in the Awakening series. After an evil sorcerer attacked the humans living in the magical realm, they fled to the sky.
Borderlands 2's main mission hub, Sanctuary, is eventually revealed to have been built on top of a giant mining ship. When the crap hits the fan and the city is under bombardment, the inhabitants turn to the only solution they can think of - lift the whole damn thing into the sky and reposition it somewhere Jack's cannons can't reach. From that point onward, the mission hub effectively becomes a floating city.
Harder settlement levels in Clonk often take place on floating islands to make life harder for the player. The backstory for one scenario off-handedly mentions an entire continent rising out of the ocean for no given reason.
The Lydian continents in A Very Long Rope to the Top of the Sky, as well as MUB-5, the Flying Mountain. Unlike many examples, these are truly continent-sized, with Terasu and Balfur in particular each requiring three separate world maps in order to display even just their accessible portions. Logos-3 used to be an example, but ended up becoming a Colony Drop instead.
Purgatorio in Nexus Clash is an archipelago of pieces various past universes hovering in an infinite void. It's a rallying point for the forces of Free Will, despite existing solely because one of the gods is a massive packrat and can't bear to part with interesting pieces of the universe every time it ends.
Pokémon Peace Squad has several examples. Pokélantis in PPS 2 is one; the Island of the Ancients in PPSEB and Angel Island (from the Sonic series) are also this. Rocketopia in PPS 3 also counts as one, as does Aerocia during the events of Chaos Adventure.
In terms of individual stages, Sky Babylon in Endless Boundaries and Aurora Sky in Infinity are these.
Two of the planets shown in the trailers for No Man's Sky (specifically, New Arion from the "Infinite Worlds" Trailer and Soleth Prime from the E3 Gameplay trailer) have floating continents, though to different degrees from each other (New Arion is completely comprised of these while Soleth Prime simply has rocks that float a few meters above the planetary surface); player can also find similar planets due to how planet generation is handled.
The Ys series is named after one of these. The second game takes place on it.
Haiku Melon's episode in Banana-nana-Ninja! World of the Damned takes place on a chain of floating islands on a distant planet.
Narbonic's genius breeding colony flying island built by hamsters. No, really.
Unicorn Jelly has flying triangles, Pastel Defender Heliotrope has rectangles, and several other JD Reitz-created worlds have flying continents of varying shapes. In fact, I can't remember a world she created that has actual planets.
Another episode has its plot centered around a floating mountain.
Storm Hawks: While most of the terras are just mountains jutting above the clouds, no floating involved, Cyclonia is eventually augmented into one of these.
Beijing temporarily becomes one of these in Teenage Mutant Ninja Turtles, after Triceratons install an engine that seals it off and sends it floating. The episode "Mission of Gravity" involves an attempt bring it back down to Earth.
Flip City in Rollbots is entirely above ground with structures held aloft by anti-gravity devices.
Actually a viable means for colonizing Venus. Oxygen floats at, conveniently enough, the area in the atmosphere that is a balmy 70 or so. An air-tight colony could use only the breathable air inside to remain bouyant. Also, since everything is in equilibrium, the colony needs no real structural strength, and so could be made enormous using current materials (the only major problem is the sulfuric acid rain, and all sorts of other horrible acids and toxic, corrosive vapours, and getting the materials there to make it, since mining from Venus's surface isn't very feasible).
Said acids and toxins could be harvested and processed into construction material.
Even if they were built on Earth or in Earth-orbit, they wouldn't be that expensive. Some NASA engineers have proposed inflatable habitats as cheap (relatively speaking) space habitats. This really wouldn't be that different.