Visitors can explore the 21-mile cave system for short 1-hour trips, or longer 3-hour tours. But for the adventurous types, the park offers an overnight expedition not only along the underground river ...

Where is the best children's museum in the United States? How about the World's Largest Toilet? And Robert Indiana's original ...

Here are all the things ... with fun names like soda straws, cave popcorn and draperies. The cave is part of a type of topography known as karst, which is found throughout southern Indiana ...