Cheongseokgul Cave is a natural cave where prehistoric humans lived, with artifacts from the Paleolithic era, such as choppers and chopping tools (hammers), points, and hand axes, discovered inside. The place stays cool even during hot summer, and is currently home to bats and golden-capped fruit bats. Nearby attractions are an artificial waterfall and a sky observatory with a valley in front of the cave available for water activities and kayaking.