Hamilton Round Barn near Mannington, West Virginia, is a rare surviving example of the state's round and polygonal barns. Built in 1911, the circular barn measures 66 feet in diameter and rises 75 feet at its center. It features a gambrel roof with a six-sided cupola, white-painted horizontal poplar clapboard siding, and a slate roof. Its unusual form gives it notable architectural significance. The West Augusta Historical Society purchased the barn in 1983, converted it into a museum, and it was listed on the National Register of Historic Places in 1985.