Great Serpent Mound

The Great Serpent Mound is an effigy mound located in Ohio, United States. Effigy mounds are prehistoric Native American structures shaped like animals or birds, found primarily in the north-central United States.1

While other mound forms existed earlier, effigy mounds began appearing around AD 300 and were built in some areas until the mid-1600s. The Hopewell and Adena cultures were significant builders of mounds in the Ohio River valley, including many conical burial mounds. Although most effigy mounds served as burial sites, some do not contain burials, and their exact purpose remains a mystery.1

The Great Serpent Mound itself is in the shape of a snake and is over 1,300 feet (400 meters) long. It is the largest effigy mound known and is a notable example of this type of ancient earthwork.1