Discovering Tennessee’s Lost Sea

The cavern walls of the Lost Sea glow with subtle lighting. The underground lake attracts more than 150,000 tourists a year.
Trey Sullins
The cavern walls of the Lost Sea glow with subtle lighting. The underground lake attracts more than 150,000 tourists a year.

SWEETWATER, Tenn. — In 1905, a 13-year-old boy playing underground in a cave in eastern Tennessee found a crawlway. The boy, Ben Sands, wriggled through the 300-foot passage, emerging into a large, dark, room half-filled with water. Sands threw dirt balls into the blackness, as far as he could, and heard them splashing.

What Sands had found was the largest underground lake in the United States, the second largest in the world. There had always been rumors about a lake, but since it was below groundwater level, the crawlway to it became exposed only during a serious drought; 1905, when Sands found it, was a year of severe drought. Since then, explorers and visitors have ventured into the cave but it was only in 1965 that the 4.5-acre lake was opened as a tourist attraction after blasting and widening the passageway leading to it. Now, people can walk rather than crawl to see the Lost Sea, the commercial name by which the lake is known.

Lost Sea is remarkable both for its size, 800 by 200 feet, and its location in an intricate cave system called Craighead Caverns. This entire part of Tennessee is made of limestone and was once the bottom of an ocean. Sixty-five million years ago, as the last dinosaurs were going extinct, the floor of the ocean rose and became exposed to the earth’s surface. Groundwater eroded the soft limestone, creating a series of irregular caves of which the Lost Sea is the lowest. Scuba divers have yet to discover the bottom of this lake, which holds more than 30 million gallons of crystal-clear water and ranges in depth from 10 to 100 feet.


“We are not just an underground lake,” says Lisa McClung, Lost Sea’s general manager. “There is so much history here. We are a Civil War trail marker and a place where Native Americans took shelter.”

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The lake, with its checkered history, attracts more than 150,000 tourists a year. White settlers used the dry caves, with their constant temperature of 58 degrees Fahrenheit, as a refrigerator to store fruits and vegetables. During the Civil War the caves were mined for saltpeter used in gunpowder and at some point they were also used to farm mushrooms and to illegally manufacture moonshine.

In the early part of the 20th century, researchers found arrowheads, jewelry, and pottery inside the caves confirming the assumption that Native Americans sheltered here. In fact, the Craighead Caverns gets its name from Craighead, the Native American chief who once owned this property.

The most fascinating discovery was in 1939, when cave explorers found bones buried in the caves’ red clay silt. George Gaylord Simpson, who was the curator of the American Museum of Natural History in New York, reconstructed the bones and found that some belonged to a newborn elk and others to the lower jaw of a Pleistocene jaguar from 20,000 years ago. The animals probably fell into the caves through a fissure and couldn’t climb back up.

“Jaguar bones have also been discovered in other parts of Tennessee,” says Larry E. Matthews, a geologist and author of Caves of Knoxville and the Great Smoky Mountains. “They probably moved north during the warmer periods between the Ice Ages. Jaguars, in recent times, lived in Texas, New Mexico, and Arizona until ranchers killed them for killing cattle.


The animals that fell into the cave were not the only ones that couldn’t climb back up. On a Lost Sea tour you will be led to the largest room, a cave about 100 feet wide and 30 feet high, with a soft, sandy floor. In the 1940s, a dance floor was constructed here and it was opened as the Cavern Tavern. The Cavern Tavern became quickly popular as the local watering hole. People gathered here to drink and dance and it was only when they had to climb the 130 steps back up that they realized they couldn’t – the high humidity and low temperature of the cave had suppressed the effects of alcohol, kicking in only when the revelers began climbing the steps. It wasn’t uncommon for people to spend the night in the cave, waiting for their inebriation to wear off.

The Cavern Tavern, like other businesses during the Depression, closed, but people still fondly remember how their relatives drank and danced here. The music, people say, sounded wonderful because of cave acoustics.

It isn’t hard to imagine how glorious music must have sounded bouncing off the walls of the huge cave. Walking through a narrow passageway, the Lost Sea comes up unexpectedly, a magnificent cave with a lake that reflects the subtle electric lighting. Glass-bottomed boats ply the lake, carrying tourists who try, discreetly, to dip their hands in the cold water to touch the blind rainbow trout swimming past. (The trout were introduced here and have gone blind because of the darkness).

It is a surreal experience and reminds me of Middle Earth from Lord of the Rings. On the walls are bunches of flower crystals, anthodites, stalactites protruding from the ceilings, and stalagmites growing out of the ground. Water, heavy with minerals, drips silently onto the floor. In a far corner of the cave, the 700 foot-high Emerald Falls is enveloped in a greenish grotto-mist that earns it its name.

The chatter of another tourist group is a reminder of the world that exists above.

Sena Desai Gopal can be reached at