In 1928, Leo Lambert and a team of excavators found a breathtaking 145-foot waterfall located over 1,120 feet below the surface of Lookout Mountain in Chattanooga, TN. Lambert named the falls after his wife, Ruby. It is the United States’ tallest and deepest waterfall. The waterfall is located at the end of the main passage of Ruby Falls Cave, in a large vertical shaft that was eroded out of limestone rock by salt water millions of years ago. Ruby Falls is believed to be 30 million years old.