Cat-Women of the Moon (1953)

Five astronauts travel to the dark side of the moon on a scientific expedition. There they discover a cave which somehow retains a breathable atmosphere. They remove their space suits and venture on, soon finding a buried city where the last members of a 2 million year old civilization greet them with food and drink. Little do they know that these eight lovely leotard-clad women are planning to steal their ship.