Navy Commander Alan Roberts is assigned to lead an expedition to Little America in Antarctica to investigate reports of a mysterious warm water inland lake discovered a decade earlier. His helicopter and its small party, including reporter Maggie Hathaway, is forced down into a volcanic crater by a fierce storm. They find themselves trapped in a lush tropical environment that has survived from prehistoric times.
Unfortunately the movie The Land Unknown is not yet available on HBO Max.
| Directing | Virgil W. Vogel | Director |
| Writing | William N. Robson | Adaptation |
| Writing | László Görög | Screenplay |
| Sound | Hans J. Salter | Original Music Composer |
| Editing | Fred MacDowell | Editor |
| Sound | Henry Mancini | Original Music Composer |
| Sound | Herman Stein | Original Music Composer |
| Art | Richard H. Riedel | Art Direction |
| Costume & Make-Up | Bud Westmore | Makeup Artist |
| Art | Ray Jeffers | Set Decoration |
| Production | William Alland | Producer |
| Camera | Ellis W. Carter | Director of Photography |
| Art | Alexander Golitzen | Art Direction |
| Writing | Charles Palmer | Story |
| Crew | Jack Kevan | Special Effects |
| Art | Russell A. Gausman | Set Decoration |
| Sound | Heinz Roemheld | Original Music Composer |
| Crew | Orien Ernest | Special Effects |
| Crew | Fred Knoth | Special Effects |
| Camera | Lew Schwartz | Assistant Camera |
| Camera | Lloyd Ward | Camera Operator |
| Visual Effects | Roswell A. Hoffmann | Visual Effects |
| Costume & Make-Up | Nevada Penn | Wardrobe Master |
| Camera | Rollie Lane | Still Photographer |
| Directing | Joseph E. Kenney | Assistant Director |
