The Mole People (1956)

Starring John Agar, Cynthia Patrick, Hugh Beaumont, Alan Napier, Nestor Paiva
Directed by Virgil Vogel
(actor & director credits courtesy IMDB.com)

The discovery of a Sumerian artifact leads a group of archaeologists to explore a giant mountain where they descend inside and discover a lost underground civilization.

After a serious introduction by a real college professor about theories about the interior of the Earth, we get a pretty crazy story about an ancient Sumerian race of albinos enslaving hideous mole people and respecting the archaeologists only because they have a "cylinder of fire," namely a common flashlight.  Still, while it's no science fiction classic, the movie is very enjoyable to watch, with the grotesque mole people pulling their victims down through the dirt, and Alan Napier, better known as "Alfred" on TV's Batman, a hoot as the power-hungry high priest who wants to kill Agar, Beaumont, and Paiva.  The mountain scenes are not well-integrated with obvious stock footage, and Agar's romance with shunned slave-girl Patrick isn't all that compelling, but I didn't care, for this is an entertaining romp and cinematic comfort food for fans of 1950s sci-fi.