Where: Williston, Florida
Don’t be misled by its ominous name—Devil’s Den is a hidden paradise. This prehistoric sinkhole-turned-spring in Florida’s heartland offers an extraordinary setting for scuba diving, spelunking, swimming, and snorkeling. Carved within a 120-foot-wide subterranean cave, its crystal-clear, 72-degree waters invite the bold to dive into an otherworldly aquatic escape, illuminated a deep blue by the sun pouring in through a natural skylight.