Caprona (also known as Caspak) is a fictitious island in the literary universe of Edgar Rice Burroughs's Caspak trilogy, including The Land That Time Forgot, The People That Time Forgot, and Out of Time's Abyss.
During World War I, a German U-boat sinks a British passenger ship and takes the survivors aboard. After getting lost in fog, the submarine surfaces near the unknown island of Caprona, a lost world where they find dinosaurs and Neanderthals.
Major Ben McBride organizes a mission to the Antarctic wastes to search for his friend who has been missing in the region for several years. McBride's party find themselves in a world populated by primitive warriors and terrifying prehistoric creatures, all of whom they must evade in order to get back safely
