The Natural Tunnel State Park in Scott County, Virginia was named after the enormous natural cave along the Appalachian Mountains. The mountain tunnel is so massive it is used as a railroad tunnel. The tunnel measures 200 feet wide and 80 feet high. It was believed to have been formed more than a million years ago. Acid-containing groundwater dissolved the limestone and dolomite along the mountain. The Stock Creek river also seeps underground into this tunnel.

Evidence of prehistoric life has been found in the area. Several fossils have been unearthed on the tunnel?s walls. With the tunnel as the centerpiece attraction, the surrounding waters and woodlands have been converted into a recreational park. People can enjoy several outdoor activities such as camping, swimming, picnicking, hiking, RV camping, and sightseeing. Visitors can stay in the provided log cabins or campgrounds.