From Ohio History Central
The Enon Mound is a large conical mound preserved by the Village of Enon in Clark County. The mound is 28 feet high and 110 feet in diameter and near the center of the village. Archaeologists who have studied the mound believe that is was built by the Adena Culture (800 B.C. to 1 A.D.) of prehistoric Native American people.
The Enon Mound is listed on the National Register of Historic Places.