History Main / LostWorld

** The Permian Islands and the Permian Continent are dominated by the descendants of Permian synapsids. The Permian Continent is populated by derived dicynodonts, who even have a few swimming members that reached the known world. The Perimian Islands, particularly the northern island, are ruled by Theriodonts, [[OurDragonsAreDifferent including a flying, poison spitting dragon]] that [[DragonRider an ancient civilization of witches modified to be large enough to ride on]].

* The ''Literature/{{Tunnels}}'' series has the Garden of the Second Sun, where it is theorized that many stages of evolution missing from the fossil record took place. It's also based heavily off of [[ThoseWackyNazis Nazi theories about a hollow earth;]] see the entry in Mythology below.
* Arnland in ''Literature/WarEagles'', an undiscovered island that is home to a tribe of Vikings, dinosaurs, strange creatures and Giant Eagles including the islands apex predator, a giant albino Eagle.
* In the original book ''Literature/TheWonderfulWizardOfOz'' by Creator/LFrankBaum, the Literature/LandOfOz is a remote country that's surrounded by a vast, unpassable desert, keeping it isolated from the rest of the world. Sequel novels would establish that there were several other "fairy countries" bordering Oz's desert, all located on an unnamed continent somewhere in "the Nonestic Ocean". Baum was never clear about what region of the world this was supposed to be in, though a popular [[{{Fanon}} fan theory]] places it somewhere near Australia. Anyway, one of the sequels had a magic spell make Oz and its neighbors invisible to the outside world and reachable only through magic, so this became something of a moot point.

** While [[Literature/JohnCarterOfMars Barsoom]] could be considered more of a PlanetaryRomance setting, it is itself full of Lost Worlds, cut off from the larger Barsoomian culture. The clearest of these is the Valley Dor at the planet's [[MysteriousAntarctica south pole]], featured in ''Literature/TheGodsOfMars''.

* %%''Film/UnknownIsland'' from 1948.

* ''LightNovel/LordOfMysteries'': The "Land Forgotten by the Gods" [[spoiler:turns out to be Europe which]] was cut off during the Cataclysm. Although most residents died, some still survive under harsh living conditions preserving knowledge forgotten by most outside.

* ''VideoGame/SonicTheHedgehog'':

* ''VideoGame/EarthBound'' has the aptly named Lost Underworld, an enormous underground cave. Unlike other areas of the game, the camera is zoomed out and your party is dwarfed by the jungle and gigantic carnivorous dinosaurs.

* ''Literature/KnownSpace'': As the name implies, Known Space is a 65 light-years bubble in space surrounding Earth where the events of Creator/LarryNiven's eponymous saga occurred. The area refers only to humanity's area of known space, other more advance races have much more extended areas and some adventures happen with humans (and sometimes alien companions) venturing outside Known Space.
* ''LightNovel/LordOfMysteries'': The 'The Land Forgotten by the Gods' [[spoiler:turns out to be Europe which]] was cut off during the Cataclysm. Although most residents died, some still survive under harsh living conditions preserving knowledge forgotten by most outside.

* There are two such places in Steve Alten's ''Literature/{{Meg}}'' series. The first one is the Marianas Trench, which is where the titular Megalodons are found. It's [[DownplayedTrope downplayed]], as people already knew of its existence, it just contained a prehistoric creature or two. Playing it much more straight is the Panthalassa sea in the sequel, ''Hell's Aquarium''. It's a primordial sea contained under a rock ceiling at the bottom of the Pacific ocean, and is home to an abundance of ancient sea creatures which have formed a comfortable food chain.
* The underground empire of K'n-yan in Hazel Heald's short story "The Mound" (revised, if not ghost-written, by Creator/HPLovecraft).
* DimeNovel hero Literature/NickCarter runs into a lost civilization of Old Norse speaking Amazons in Bolivia.

* Neverland, from J.M. Barrie's ''Literature/PeterPan''. Subverted in that it's a world created by the dreams and stories of children, so only they can really visit it.

Besides [[DesertedIsland islands]], [[JungleOpera jungles]], isolated plateaus and the [[MysteriousAntarctica frozen poles of the Earth]], the Lost World can exist in even more mysterious places, such as outer space, the [[EldritchOceanAbyss bottom of the ocean]], or [[BeneathTheEarth deep within the planet]] itself. Occasionally treated more seriously, as a venue for playing with alternate evolutionary pathways.

* ''Literature/JourneyToTheCenterOfTheEarth''
** Several recent authors such as James Rollins or Jeff Long have followed Verne's example, placing their modern Lost World tales underground, to justify such places having gone undiscovered.

** "Skartaris"[[note]]Named after the volcano through which Creator/JulesVerne's adventurers made their ''Journey to the Center of the Earth''[[/note]] (a world located within the hollow Earth, accessible through a portal in the Arctic wilderness), which is the setting of Mike Grell's ''ComicBook/TheWarlord'' (though other DC Universe characters would visit there from time to time as well). An episode of ''[[WesternAnimation/JusticeLeague Justice League Unlimited]]'' is set there. It was later {{retcon}}ned into being AnotherDimension.

*

* The lost world of Aphrodisia (home to the [[LadyLand all-female Lubby-Dubby Tribe]]) in ''Film/CarryOnUpTheJungle''.

%%* ''Literature/{{Fragment}}'': [[DeathWorld Henders Island]] plays this so literally it hurts.%%ZCE, don't write reviews.

* The Hy-yi-yi islands, home of the [[http://en.wikipedia.org/wiki/Snouters Snouters,]] are a Lost World without the ruins. Lots of goofy-looking critters, but for once they're not trying to kill you.

[[folder:Light Novels]]
* ''LightNovel/LordOfMysteries'': The 'The Land Forgotten by the Gods' [[spoiler:turns out to be Europe which]] was cut off during the Cataclysm. Although most residents died, some still survive under harsh living conditions preserving knowledge forgotten by most outside.
[[/folder]]

* In ''Anime/SerendipityThePinkDragon'', the island is this to some degree; this is the reason its discovery by Smudge is so exciting to him, and so distressing to its natives.
* In the ''Anime/SpiderRiders'' franchise, a place aptly named the "Inner World" exists deep beneath the earth in a gigantic cavern filled with plants, an ocean and giant humanoid insects.

* New Zealand. Up until about 600 years ago, it was the last major landmass on Earth still dominated by dinosaurs (albeit of the avian variety): its largest herbivore was the 10-foot-tall flightless moa, while its top predator was the giant Haast's eagle. New Zealand is also home to real-life relics from the Mesozoic such as the Tuatara and the Pepeketua frogs. [[TheMagicGoesAway Then the Polynesians showed up.]]

** ''VideoGame/PokemonScarletAndViolet'': The Great Crater of Paldea contains one of these, known as Area Zero. It is regarded as exceedingly dangerous, and almost nothing is known about it as a result. It contains wonders so fantastic that the Ancient Empire of Paldea bankrupted itself over centuries funding failed expeditions to try and obtain some, forcing itself to merge with its neighbors out of an act of self-preservation to form the modern Paldea region. Among the wonders are Herba Mystica that can fully heal a Pokemon on death's door that even Pokemon centers are unable to help. It also contains powerful and dangerous Pokemon, among them Pokemon from the prehistoric past and Pokemon from the distant future, as well as the crystals that allow Pokemon to Terastallize. And the scary part is not all of these Pokemon are there as a direct result of the Big Bad's time travel experiments, as the book containing all known information on Area Zero and also contains records of all known Paradox Pokemon has existed since they were a child.
* ''VideoGame/ReturnToMysteriousIsland'' and its sequal play this fairly straight, the second game moreso than the first.

-->'''Cpt. Taylor:''' It's like...an unknown valley that time forgot, where everything grows huge.
-->'''Craig:''' [[DeadpanSnarker That's a shock. I decided to follow]] [[WeirdnessMagnet you guys]], [[DeadpanSnarker and now I'm in the Land-of-the-Giants Lost World]].

* ''VideoGame/EarthBound'' has the aptly named Lost Underworld, an enormous underground cave. Unlike other areas of the game, the camera is zoomed out and your party is dwarfed by the jungle and [[EverythingsBetterWithDinosaurs gigantic carnivorous dinosaurs]].

* It is implied in the ''Film/SuperMarioBros'' movie that dinosaurs have escaped from their parallel dimension into our world and humans into theirs throughout history, which would make the parallel world a sort of "Lost World".

* ''VideoGame/PokemonMysteryDungeonExplorers of Time/Darkness'' features one of these in the penultimate level, the aptly-named Hidden Land. The Hidden Land is so-called because it is ''only exists within a split second of time,'' meaning that [[TimeStandsStill time must be stopped]] before it can be visited.

* ''Literature/AStrangeManuscriptFoundInACopperCylinder'' by James De Mille is another early example.

* ''A Strange Manuscript Found in a Copper Cylinder'' by James De Mille is another early example.

* ''The Diamond as Big as the Ritz'' by Creator/FScottFitzgerald is all about an isolated pocket of fantastic wealth hidden in Montana. It's been successfully hidden by its wealthy, urbane, and autocratic owners for generations -- but by the time of the story airplane overflight becomes a problem...

* ''ComicBook/{{Cavewoman}}'' is supposedly set in the late Cretaceous (with the [[JunglePrincess main character]] having arrived there by time travel) but everything can be found in the primal jungle from dinosauts to giant snakes, [[FrazettaMan hominids]], [[BigfootSasquatchAndYeti yetis]] and... [[AllTrollsAreDifferent trolls]]. Plus, one of the issues is named "Pangaian Sea".

* ''ComicBook/{{Cavewoman}}'' is supposedly set in the late Cretaceous (with the [[JunglePrincess main character]] having arrived there by time travel) but everything can be found in the primal jungle from StockDinosaurs to giant snakes, [[FrazettaMan hominids]], [[BigfootSasquatchAndYeti yetis]] and... [[AllTrollsAreDifferent trolls]]. Plus, one of the issues is named "Pangaian Sea".

*** Pal-ul-don, the setting for ''Tarzan the Terrible'' (1921), a region of central Africa surrounded by mountains and near-impassable swamps, is home to numerous forms of prehistoric life including a carnivorous(!) variant of ''[[StockDinosaurs Triceratops]]'', as well as three distinct forms of FrazettaMan: the black and hairy Waz-don, the white and almost hairless Ho-don, and the bestial Tor-o-don.

* Creator/{{Atari}}'s ''Pinball/MiddleEarth'' pinball takes place in one of these, complete with [[PantheraAwesome feral cats]], [[StockDinosaurs bloodthirsty dinosaurs]], [[KillerGorilla giant apes]] and [[{{Kaiju}} even bigger monsters]].