We drove to Chattanooga, Tn on Sunday and visited Ruby Falls. It was pretty cool. You take an elevator 260 ft down into the cave and then walk 1/2 mile to the falls and 1/2 mile back. The falls are the largest continual underground waterfall in the US falling 145 feet.There were a lot of natural formations along the path that look like different objects. It was a little expensive for our family, but it was cool to do one time.