A century ago, a teenage boy exploring a cave in Tennessee squeezed through a narrow passage and stumbled upon something few people had seen before, a vast underground body of water that would become known as the Lost Sea.
The discovery was made in 1905 by 13-year-old Ben Sands inside Craighead Caverns, near Sweetwater, Tennessee. What initially looked like a small opening in the cave eventually led him to a huge chamber containing an underground lake.
