Dr. Abner Perry (Peter Cushing), a British Victorian scientist, and his US financier David Innes (Doug McClure) make a test run of their Iron Mole drilling machine in a Welsh mountain, but end up in a strange underground labyrinth ruled by a species of giant telepathic flying reptiles, the Mahars, and full of prehistoric beasts and cavemen.
| MPAA Rating: | PG |
| Genre: | Adventure, Fantasy, Sci Fi |
| Country: | United Kingdom, United States |
| Produced By: | John Dark, Harry N. Blum, Max Rosenberg, Milton Subotsky |
| Directed By: | Kevin Connor |
| Written By: | Edgar Rice Burroughs, Milton Subotsky |
| Cast: | Helen Gill, Caroline Munro, Keith Barron, Peter Cushing, Andee Cromarty, Sean Lynch, Godfrey James, Anthony Verner, Michael Crane, Cy Grant, Bobby Parr, Doug McClure, Robert Gillespie |
| In Theaters: | Jul 01, 1976 |
| Runtime: | 1 hour 29 minutes |
| Production: | Amicus Productions |
| Budget: | $1,500,000 |
| Available On: | Amazon, Itunes, Vudu |
| Read More On: | Wikipedia |