The Natural Tunnel Caverns and Cave is so large that it is also used as a railroad tunnel. It is acknowledged that Daniel Boone was the first European to see it in the 18th-century.
More than 850 feet long and 10 stories high, Natural Tunnel was naturally carved through a limestone ridge over thousands of years. William Jennings Bryan called it the “Eighth Wonder of the World.” Other scenic features include a wide chasm between steep stone walls surrounded by several pinnacles, or “chimneys.”