Bull Shoals Caverns

Bull Shoals Caverns is a limestone cavern located in Bull Shoals, Arkansas. 
The caverns were created approximately 350 million years ago, during the Ordovician period and were carved out by water method. The caverns were formed by water seeping into the cracks of the rocks, gradually enlarging the cracks and dissolving the surrounding rocks. There is an underground river that flows through the caverns.
Bull Shoals Caverns has been open since 1958.