The Lost Sea is America’s largest underground lake and Registered National Landmark located in beautiful Sweetwater, Tennessee. Get ready to take an unforgettable adventure as you tour the caverns and underground lakes and learn about the Lost Sea’s incredible history. 

(423) 337-6616

140 Lost Sea Road
Sweetwater, TN 37874 

Your Lost Sea adventure begins with a guided tour of the caverns. This involves a ¾ mile round-trip walk on wide sloping pathways. While touring the caverns and underground lake our guides will tell of the cavern’s exciting and colorful history. They will also explain the fascinating geological development of the immense cavern rooms and rare formations. At the bottom of the cave you will take a boat ride on The Lost Sea, America’s Largest Underground Lake.

We are open every day of the year for tours (except Thanksgiving and Christmas Day). The tour takes approximately 1 hour and 15 minutes. Either before or after your tour you might want to visit the Lost Sea Village where we have several shops.  Or take a walk on our self-guided Nature Trail. The gift shops in the Village are open seasonally.

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