Clingmans Dome Observation Tower and its curved ramp to the top. This massive structure stands 45 feet tall with a 375-foot ramp. Built in 1959, the tower sits on Clingmans Dome, the highest point of the Great Smoky Mountains at an elevation of 6,643 feet. The tower was constructed as part of the National Park Service’s Mission 66, a program to build hundreds of buildings.