Fontana Dam in western North Carolina is the record holder. This hydroelectric dam in Swain and Graham counties is 480 feet tall. The Tennessee Valley Authority built it in the 1940s to meet growing electricity demands, and it provided critical energy for aluminum production in the last months of World War II.

The Fontana Dam Visitor Center, near Fontana Village, is open 9 a.m–6 p.m. daily May through October (except major holidays). Visitors there can watch the dam’s water being released after it generates electricity, and see interesting maps, videos and displays. tva.com