This is a Rare Mexican Sc-Fi! film from director Alfredo B. Crevenna who go on to direct many Mexican horror and Sci-Fi films over the next 25 years. An Expeditionary Team Journey to the Center of The Earth in search of very rare minerals and artifacts from the core however, instead they encounter giant bat creatures, and other horrible monsters. Considered to the Mexican Version of Jules Verne's "Journey to The Center of The Earth" except with a horror twist, great!! Sci-Fi Horror Adventure film. B/W from 1959 Spanish Uncut Version W/English Subtitles on DVD-R.