Dunbar Cave State Park is a 110 acre (450,000 m²) park in Clarksville, Tennessee, situated around Dunbar Cave. Dunbar Cave is the 280th largest cave complex in the world, stretching 8.067 miles (13 km) inward. In front of the cave entrance is a large concrete poured structure with three distinct arches. The cave is located in an area of karst topography, including sinkholes, springs, and limestone bedrock. The manmade Swan Lake also sits in front of the cave.