Deep inside a mountain in east Tennessee is The Lost Sea, part of the historic Craighead Caverns cave system and listed by the Guinness Book of World Records as America’s largest underground lake. The Lost Sea was first discovered by settlers in the 1820s, again by Confederate soldiers in 1863, and once more in 1905 by a 13-year old boy named Ben Sands: as he wiggled through the cave’s muddy opening, 300 feet (91.4 meters) underground, he found himself in a room half filled with water. He described how he threw mudballs into the blackness that surrounded him, and hear nothing but splashes. The expansiveness of the Lost Sea is still unknown, but the visible part is 800 feet long by 220 feet wide (244 by 67 feet). More than 13 acres of water have been mapped, but no end to the lake has yet been found.
