The Adena culture was a Native American culture group that existed from c. 800 BC to AD 100. They were one of the earliest of the Mound Builder cultures that flourished in eastern North America before the time of European contact. Adena culture's most lasting artifacts were substantial earthworks, some of which still survive and can be studied by archaeologists. The Serpent Mound complex in Adams County, Ohio may have originally been the work of Adena peoples.
