Juan Piquer Simon, best known for such horror films as
Pieces and
Slugs, tackled the Jules Verne story with poor results.
Kenneth More leads the expedition to the earth's core, where he and his party are menaced by gorillas, dinosaurs, and other assorted creatures. The special-effects are less than inspired, although More does his best in the lead and Spanish-horror fans will enjoy seeing veterans Jack Taylor and
Frank Brana among the cast. Simon would return to Verne for inspiration with his 1981 film
Monster Island. ~ Robert Firsching, All Movie Guide