Försvunna i okänd värld was released in the year 1957。Försvunna i okänd värld is also called as The Land Unknown, Prigionieri dell'Antartide, Oasis des tempêtes, Oasis de la terreur, Flug zur Hölle, Etelämantereen salaisuus。

On a naval expedition to Antarctica, three men and reporter Maggie Hathaway crash-land in a crater 1000 m below sea level. There, they encounter steamy tropical forest, dinosaurs, carnivorous plants, and human footprints, as Maggie's clothes become more and more abbreviated.