The Jacob Woodruff House is a two-story octagonal house constructed of concrete walls, featuring a large, windowed cupola, and metal roof. It is located in Ripon in the U.S. state of Wisconsin, and is listed on the National Register of Historic Places. Jacob Woodruff was a member of and the librarian for the Wisconsin Phalanx in 1846, a communal society based on the philosophy of Charles Fourier, a French socialist. References Houses in Fond du Lac County, Wisconsin Houses completed in 1850 Houses on the National Register of Historic Places in Wisconsin Octagon houses in Wisconsin Ripon, Wisconsin National Register of Historic Places in Fond du Lac County, Wisconsin Architecture related to utopias