Ruby Falls is home to the tallest and deepest underground waterfall open to the public in the United States. Over half a million guests visit the thundering waterfall annually, located deep within Lookout Mountain in Chattanooga, Tennessee. Guided tours explore the cavern trails and ancient geological formations. Sweeping views of the Tennessee Valley are abundant from historic Lookout Mountain Tower, Blue Heron Overlook, and the Ruby Falls Village Plaza. Committed to cave conservation and environmental sustainability, Ruby Falls is the first attraction in the United States to earn certification from Green Globe and is recognized as a leader in tourism sustainability.