Devil's Den

Devil's Den is a prehistoric underground spring enclosed in a collapsed karst dome — a dry cave entry leads down to the water's surface, where a circular cavern opens 30 feet below in a limestone grotto bathed in surreal turquoise light filtering through the roof opening. The spring discharges roughly 100 million gallons per day at a constant 68 degrees Fahrenheit. Fossilized bones of Pleistocene megafauna including mammoths, ground sloths, and giant armadillos were discovered in the sediment here, making the site significant beyond its diving appeal. The space is entirely within the daylight zone — no cave certification required — but the single entry and exit point and enclosed geometry mean strict buoyancy control is essential to protect the visibility and the archaeological integrity of the bottom.