Gua Kelawar is more than just a home for bats; it is a "time machine" for geologists. The cave consists of two main chambers covering roughly 1,000 square meters. One of its most significant features is a layer of old sea shells encrusted onto the cave walls and roof. Radiocarbon dating has shown these shells to be approximately 5,000 years old, proving that sea levels in Langkawi were once 2 meters higher than they are today. Local folklore also links the area to legends of Gedembai, a giantess with the power to turn living things into stone, which locals used to explain the cave's strange rock formations.