The Great Serpent Mound is a prehistoric effigy earthwork of a serpent uncoiling located on a wedge-shaped, slightly convex ridge in the rolling hills of southern Ohio where it overlooks a waterway called Brush Creek. The Serpent Mound is believed to be created by the Adena culture, who lived in the Ohio Valley from around 800 b.c.e. to around 100 c.e. The Adena were renowned for their elaborate earthworks and their creation of “sacred circles” as part of their cosmology. However, no artifacts related to the Adena have been found within the Serpent Mound.