Originally formed by the Adena Culture, maintained by the Hopewell, and later remodeled by the Fort Ancient people, the Great Serpent Mound in Peebles, Ohio, is the largest serpent effigy mound in the world. Located on the Serpent Mound crater plateau, the mound is 1,348-feet-long and about 3 feet high. The soil for the earthworks was carried up from the Ohio Bush Creek below and the mound was built in stages. While there is some evidence that the mound was intended to be an astrological calendar, the actual angles are slightly off (by less than 2 degrees of arc) and also require viewing positions that aren’t well marked.
