In 1905, a 13-year-old boy stumbled upon America’s largest underground lake in Craighead Caverns, Tennessee. This expansive chamber, referred to as the Lost Sea, showcases traces of Indigenous habitation and mining activities from the Civil War. Nowadays, visitors have the opportunity to navigate the vast cavern and embark on a captivating boat ride over the hidden waters. The total size of this geological marvel continues to spark intrigue and investigation.