There are many places in the U.S. that are considered to be 'secret' by the locals and by those who have yet to discover them. Underground caverns, unknown swimming holes, and quiet walks through the woods have long been coveted by those who know of their existence, and the Lost Sea of Tennessee is among them. This cave, located in Sweetwater, Tennessee, isn't as much of a secret as it is a lesser-known underground destination. Its uniqueness lies in the fact that it's partially a cave, and partially an underground lake, which makes exploring it quite the adventure.


Visitors to the Lost Sea have a few options when it comes to how they can explore this small - but pretty awesome - cave system. Several parts of the cave can also be explored depending on which tour visitors choose to take, making for an even more expansive adventure.

Related: These Tours Of Kentucky's Mammoth Cave Are Worth Taking, Ranked By Difficulty

About The Lost Sea And Its Cave

The cave that hovers above the Lost Sea will take visitors directly to the underground lake, involving a walk that's less than a mile. The cave's features continue throughout and below the surface of the water, with divers having mapped out a whopping 13 acres thus far. Therefore, much of the cave and its map is still a mystery, at least, in regard to what lies below sea level. Those visiting the cave are not permitted to go cave diving since that's left to expert divers, but they are permitted to explore the cave via boat and on foot.

Although the cave has a reputation for being the largest known underground lake in the country, that doesn't mean that it's well-known by everyone. In fact, in regard to Tennessee's other natural features, this one is not as visited as many others. However, the underground lake is registered as a National Landmark, but it's what lies beneath the cave that's truly astounding. With such underground scenery as this, it's amazing that the cave isn't visited more. Located right in Chattanooga (Sweetwater, specifically), it has some pretty worthy attractions to compete with - but here's why it should be on everyone's list.

What Lies Beneath

When exploring the cave's underground lake, visitors will happen upon what are known as 'cave flowers.' These are also known scientifically as anthodites, which make up beautiful water-dwelling plants that can be found throughout the water. Additionally, the Lost Sea is home to a species of trout that live and thrive underground, making for a truly miraculous ecosystem.

During various cave diving excursions, professional divers have discovered that the lake is only just beginning to scratch the surface of what exists underneath this cavern. Not only is the lake itself quite deep but underneath the surface of the water, there are additional underwater caverns, called 'rooms' that are completely flooded and unreachable without proper equipment.

Touring The Cave And The Lost Sea

The Lost Sea tour begins with a hike through the cavern until visitors reach the water's edge. The first trek is only about three-quarters of a mile and features wide, sloping pathways on which to be walked. Along the way, a tour guide will detail the incredible history of the cavern which includes all the ways the Cherokee Indians used it, as well as how it was later mined by Confederate soldiers for saltpeter. Visitors will be able to see various formations throughout the cave as long as the natural crevices and shapes it has taken on through the centuries, before coming upon the Lost Sea.

Here, visitors will board glass-bottom boats which will take them across the large underground lake, which spans a distance of four acres. The Lost Sea resides at a depth of 140 feet below sea level, and returning to the cave opening requires some incline walking.

  • Tour Length: 1 hour, 15 minutes
  • Cave Temp: 58 degrees year-round
  • Admission: $23.95 for adults, $13.95 for children

Wild Cave Tour

Another option for seeing the cave is a Wild Cave Tour. This tour takes groups through the cave by means of down-and-dirty exploration and is available for schools, camps, churches, scouts, and the like. Tour-takers will get an up-close and personal look at the cave's formations and a deeper glimpse into its history. Crawling through crevices and poking through dirt in the cave should be anticipated on this tour, as guests have the chance to be their own anthropologists when exploring this route. Guests will also have the chance to see lesser-toured cave rooms, and many of them are not open to the general public.

  • Tour Length: Overnight trip starting at 6 PM & daytime tours available
  • Minimum Group Size: 12 people
  • Reservations: Two weeks in advance
  • Admission: Overnight trips start at $45/person, day tours start at $35/person
  • Included: Lost Sea tour, boat ride, spelunking tour, and overnight stay (camping)

Next: Krubera Cave Is The World's Deepest, And Getting To The Bottom Isn't Even The Half Of It