At the Earth's Core is currently streaming on Tubi

At the Earth's Core (1976)90 minAdventure, Fantasy, Science FictionRating 50/100

When two explorers drive a large drill into the center of the Earth, they discover a hidden world where humans are enslaved by prehistoric beasts.

Cast: Doug McClure, Peter Cushing, Caroline Munro, Cy Grant, Godfrey James, Sean Lynch, Keith Barron

Director: Kevin Connor