A happy childhood memory from east Tennessee was The Lost Sea Adventure. Although The Lost Sea Adventure has the largest underground lake in the United States, there are many caves in this limestone-filled region., making it a standout attraction.

How Deep Is The Lost Sea’s Water?

Uncertain in size, its top chamber contains water that covers 4.5 acres at a depth of 70 feet and is supplied by a number of underground sources. It has been repeatedly pointed out to the incredibly patient tour guides at the Lost Sea that this is a freshwater lake, not a saltwater sea.

Lost Sea Opening Hours:

Open every day except Christmas and Thanksgiving

• Winter (Nov-Feb): 9am -5 pm
• Spring (Mar & April) and Fall (Sept & Oct): 9am- 6pm
• Summer (May-Aug): 9 am- 7 pm (8 pm in July)

Can You Swim In The Lost Sea?

The Lost Sea is it safe to swim in? No, but your Lost Sea Adventure trip already includes a glass-bottom boat ride over America’s Largest Underground Lake. It’s a unique experience because the cave and lake are lit by subdued colored lights.

Is Fishing Permitted In Tennessee’s Lost Sea?

Interestingly, fishing is prohibited. Under the calm waters of the four-and-a-half-acre lake, divers have discovered an even larger series of chambers completely filled with water. The lake’s end hasn’t been located, despite plots covering more than 13 acres of water.

The water’s constant temperature in the Lost Sea is 54 degrees. Its 800-foot length and 220-foot width are visible above the water. Below, it is unclear how severe the damage is. Fishing is not permitted, but rainbow trout have been introduced to the lake.

Why Is The Lost Sea Adventure Taking Place?

The Lost Sea Expedition. The largest underground lake in the nation as well as a sizable number of anchorites, or cave flowers, can be found in the caves. A boat ride on the lake follows a guided tour to the cave’s bottom. The Lost Sea is a National Natural Landmark in the US.

The History Of Lost Sea

The Lost Sea is part of the larger Craighead Caverns, which stretch north from Sweetwater to Madisonville. The abundance of limestone in the region accounts for the numerous caves in the east and middle Tennessee (over 10,000 have been discovered so far). 250 million years ago, this area was covered by a shallow inland sea leading to the limestone formation. 90 million years ago, the sea dried out as the land was uplifted and surface water began to trickle through the limestone bedrock, dissolving it and forming these caves, large and small.

For thousands of years, people have known about and used caves. The Cherokee used the “Council Room,” a large cave near the entrance, as a meeting place. There, numerous artifacts, including jewelry and pottery, have been amassed. Later, since the caves maintain a consistent 58 degrees year-round, white settlers in the area used them as food storage.

In addition to saltpeter mining, Confederate soldiers left behind graffiti in these caves for us to enjoy. Carbon dating has confirmed that the names and dates written in black on the cave walls were created using torch ash from the soldiers. (The names in white were carved into the rock more recently; only the names in black are historically significant. It’s interesting to see that the “I was here” sentiment hasn’t changed much over the years. )

The Regular Tour For Lost Sea

The entrance drive of The Lost Sea takes you past several parking lots, a group of buildings to your left, one building to your right, and a collection of buildings as you turn off Highway 68. The building on the right that houses the cave entrance and ticket office is where you should park as close to as possible. Although you can purchase your tickets in advance online, you will still need to check in at the box office to be assigned to the following tour.

You must be reasonably mobile to participate in the Regular Tour, which lasts approximately an hour and fifteen minutes. It takes about 3/4 of a mile to complete the tour, during which you descend 140 feet to reach the lake (and, more importantly, return 140 feet to the surface). Although there are good handrails to use, the walkway is wide and occasionally steeply sloping.

Claustrophobia shouldn’t be a problem on the standard tour because the cave rooms are very spacious unless you absolutely cannot stand the thought of being underground.

Stalactites, stalagmites, authorities (rare crystalline formations), an old moonshine still, Civil War graffiti, and a waterfall can be found on the route to and from the lake. The highlight for everyone is when they turn off the lights, which will plunge you into complete darkness for about a minute.

Tips For The Lost Sea Tour

Put on grippy, sturdy shoes. Due to the high humidity in the cave, the pathways are made of packed dirt and are occasionally slippery. No one slipped and fell, but it could have easily happened several times. As needed, use the handrails.

I would recommend bringing a light jacket or wearing long pants because the caves are always 58 degrees. But the high humidity keeps the temperature at 58.

Before your tour, use the restrooms close to the ticket office. Up until the end of the tour, this will be your final opportunity.

Check out the largest trout ever caught in the lake as well as the Pleistocene jaguar footprints and skull. Both are kept in cases close to the ticket counter.