Despite its intimidating name, there are no actual crocodiles living in Gua Buaya today. The name is derived entirely from the physical resemblance of the limestone entrance to a crocodile’s head. Geologically, the cave is a natural river tunnel formed thousands of years ago by an ancient underground stream that carved through the limestone when sea levels were significantly lower. Today, it serves as a "shortcut" for boatmen. Legend and local lore sometimes suggest that crocodiles once inhabited these waters in abundance, but now the only "beasts" visitors encounter are the soaring Brahminy Kite eagles and macaques that live in the surrounding mangroves.