Dunbar Cave State Park is a 110 acre protected area in Clarksville, Tennessee. Dunbar Cave is the 280th largest cave complex in the world, stretching 8.067 miles inward. The cave is located in an area of karst topography, including sinkholes, springs, and limestone bedrock. In front of the cave entrance is a large concrete poured structure with three distinct arches and the manmade Swan Lake.