At the Earth's Core

A runaway drilling machine rips through the Earth at terrifying speed and breaks into a hidden twilight realm beneath the crust. Inventor Dr. Abner Perry and adventurer David Innes end up in this primeval world, where prehistoric beasts, half-human tribes, and carnivorous flora threaten every step. The pair try to make allies and survive long enough to understand the land they accidentally uncovered, while a fierce princess becomes both an ally and a complication. Tension comes from constant motion and narrow escapes, with the focus on spectacle and the clash between modern technology and primeval dangers, without revealing how any conflicts finally resolve.

Released in 1976, the film was directed by Kevin Connor and produced by Milton Subotsky, adapting material by Edgar Rice Burroughs. It stars Doug McClure as David Innes, Peter Cushing as Dr. Abner Perry, and Caroline Munro as Princess Dia, combining British genre filmmaking with pulp fantasy roots.

At release the movie earned modest returns at the box office, doing better with international genre audiences than with mainstream critics. Over time it found additional viewers through television showings and home video, which helped it retain visibility among adventure and sci fi fans.

Over decades the film built a small cult following, mainly among fans of 1970s creature features. Its big set pieces, like the burrowing machine and strange flying reptiles, get cited by enthusiasts who appreciate practical effects and period production design. Caroline Munro's presence and the film's hearty, pulpy tone have kept it in genre conversations.

Critical reaction was mixed, reflected in an average user rating around 5.0 out of 10. Reviewers tended to praise the imaginative creature and set work while noting thin plotting and occasionally wooden dialogue. The movie plays up spectacle over nuance, returning viewers to a straightforward, old-school sense of adventure and visual wonder rather than modern psychological depth.