First appearance: Beyond the great south wall: the secret of the Antarctic
Author/Creator: Frank Savile
Media: Novel
Year: 1901
Located: Antarctica
Plot/Premise: An expedition to the Antarctic searches for the lost treasures of the Mayans. The explorers encounter Cay, a dinosaur worshipped by the Mayans.

First appearance: Le Peuple du Pôle (The People of the Pole)
Author/Creator: Charles Derennes
Media: Novel
Year: 1907
Located: Secret valley at the North Pole
Plot/Premise: During an expedition to the North Pole, French aeronauts Jean-Louis de Venasque and Jacques Ceintras stumble upon an alien society of technologically-advanced reptilian humanoids living in a secret enclave that has been isolated from the world for millions of years. Archaic forms also persist in the form of "gigantic and bipedal reptiles."
Sequels/Other appearances: League of Extraordinary Gentlemen (Alan Moore)

First appearance: Plutonia (Utazás Plutóniába)
Author/Creator: Vladimir A. Obruchev
Media: Novel
Year: 1924
Located: Earth's interior
Plot/Premise: A Russian Artic expedition inadvertently enters the interior of the earth. Building a raft they travel on a "river of time" from which they observe, the further south they go (on the earth's inner surface) the older, geologically, the life becomes. They encounter a wide variety of dinosaurs and eventually escape only to find a surface world engulfed in world war.

First appearance: The Greatest Adventure
Author/Creator: John Taine
Media: Novel
Year: 1929
Located: Antarctica
Plot/Premise: When a sea captain brings a baby dinosaur to the home of a wealthy, brilliant scientist, it triggers an expedition that leads to an unexplored, quake-shaken Antarctica and to a lost world over-run with the "dinosaurs" that are not what they appear.

First appearance: The Land Unknown
Author/Creator:
Media: Film
Year: 1957
Located: Antarctica, 3000 feet below sea level
Plot/Premise: A Navy expedition is sent to explore a mysterious warm-water region shrouded in the ice of Antarctica. When a fierce storm drives them into a cloud bank, their helicopter is disabled by a collision with a pterodactyl. Descending through the heavy fog into a deep chasm, they encounter a hot, tropical landscape of prehistoric terror.
Adaptations: The Land Unknown (Comic, 1957, Dell) by Alex Toth

First appearance: X-Men #10
Author/Creator: Stan Lee and Jack Kirby
Media: Comic
Year: 1965
Located: Antarctica
Plot/Premise: The Savage Land is a tropical region surrounded by volcanoes deep in Antarctica, created over 200 million years ago by the alien Nuwali as one of several planetary "game preserves" for the mysterious godlike Beyonders. The Nuwali stocked the Land with Earthly life of the era, most notably dinosaurs; as Earth's flora and fauna changed over succeeding millions of years, they supplemented their preserve with prehistoric mammals and early hominids, or "Man-Apes."

Sequels/Other appearances: "The Hunter and the Hunted" (Spider-Man and His Amazing Friends Spider-Man TV Show, 1981); X-Men (TV series, 1992); "Stranger From a Savage Land" (The Super Hero Squad Show TV show, 1981); Next Avengers: Heroes of Tomorrow (Video film, 2008); X-Men: Children of the Atom (Video game, 1994); Genesis X-Men (Video game, 1993) X-Men 2: Clone Wars (Video game, 1995); X-Men Legends II: Rise of Apocalypse (Video game, 2005); Marvel Super Hero Squad (Video game, 2009)