The outer embankment of the Great Mound earthwork was constructed about 160 B.C. by the Adena people. Later, the Hopewell people added a small mound containing four human skeletons, cremations, bone awls, pottery shards, projectile points, and a platform pipe, which were excavated during the summers of 1968 and 1969. The main function of the Great Mound is believed to have been as a meeting area for religious ceremonies. A gateway provided access to the central platform where the ceremonies took place. The outer ring may have served as a seating area, but it was probably constructed to block others from viewing these ceremonies. The Adena and Hopewell people reached their peak between 200 B.C. and 300 A.D. The Great Mound is the largest surviving earthwork of its kind in Indiana, and its construction required moving more than 16,300 cubic yards of soil.