The Adventures of Superman
The Unknown People, Pt. 1
S1 E25:
Ordered to write a story about the deepest oil well in history, newspaper reporters Clark Kent and Lois Lane are amazed to discover that the well is closed and the countryside rife with terror following the realization that they have drilled into another world in the center of the Earth during the Superman adventure, "The Unknown People, pt. 1." Strange creatures emerge from the aperture to add to the excitement. It's the first of a two part Superman TV program. Part 1 of 2
Starring
Beverly Washburn, Walter Reed, Jeff Corey