At the Earth's Core

At the Earth's Core is a 1976 British-American fantasy adventure set in the Victorian era. Dr. Abner Perry, a scientist, builds a giant drilling machine called the Iron Mole and tests it with his American associate David Innes. The test goes wrong when the machine cannot be steered, and it burrows straight down, carrying the two men into a hidden world beneath the Earth's surface. There they find a prehistoric land of strange plants and creatures, and a civilization of intelligent flying reptiles that keep humans as slaves through mind control. David becomes attached to Dia, a young woman of this underground people, and when she is chosen for sacrifice, he and Perry organize the human captives to rise against their rulers.

The film was directed by Kevin Connor and written by Milton Subotsky. It followed Connor's The Land That Time Forgot, another adaptation of an Edgar Rice Burroughs story, and the two films share a lead actor in Doug McClure, who plays David Innes. Peter Cushing appears as Dr. Abner Perry, with Caroline Munro as Princess Dia and Cy Grant as Ra.

Made on a budget of about two million dollars, the film took roughly three million dollars worldwide. Its ratings sit in the middle range: 5.1 out of 10 on IMDb from around 6,100 votes and the same score on TMDB from far fewer votes, while a film critics' rating of 4.9 out of 10 from 10 reviews is close to those audience figures.