William Hill Polygonal Barn

William Hill Polygonal Barn, also known as the Hill-Mershon Barn, is an eight-sided barn located at Bloomingdale, Parke County, Indiana. It was built about 1905, and is a two-story, octagonal frame building. It measures 30 feet in width and is topped by a sectional cone roof topped by an octagonal cupola.

It was added to the National Register of Historic Places in 1993.