The 300-acre Hopewell Mound Group is the type site for the Hopewell culture. Early archeologists named the site for its owner, Mordecai C. Hopewell. The general shape of the Hopewell Mound Group is a parallelogram 1,800 feet long on the east and the west sides and 2,800 feet long on the north and south. Archeologists estimated that the walls were originally 35 feet wide at the base and enclosed an area of 111 acres. A smaller square enclosure with sides 850 feet long is connected to the east side of the parallelogram. Remnants of the east, west, and north walls are visible. Two earthworks features are located within the parallelogram, one circular and one D-shaped. Three of the seven mounds in the D-shaped enclosure are joined. Their original size is estimated to be 500 feet long, 180 feet wide, and 30 feet tall. This is the largest known mound constructed by the Hopewell culture, and a remnant of it is visible today.