Craighead Caverns in eastern Tennessee is a vast cave system best known for The Lost Sea, the largest underground lake in the United States and the world’s second-largest non-subglacial one. The caverns also feature anthodites, stalactites, stalagmites, and an underground waterfall. Used by the Cherokee as a council place, they later supplied Confederate saltpeter and sheltered moonshiners. The Lost Sea entered local lore after Ben Sands found it in 1905, and later exploration showed the system extended beyond sight. Fossil discoveries in 1939 and 1940 added scientific importance, and in 1974 the caverns were recognized as a National Natural Landmark.