Cowan Creek Circular Enclosure - Credit: Wikimedia Commons
The Cowan Creek Circular Enclosure (33CN11Koleszar, Stephen C. An Archaeological Survey of Southwestern Ohio. Columbus: Ohio Historical Society, 1970, 15.) is an earthworks complex in the southwestern part of the U.S. state of Ohio. Named for its location near the stream known as Cowan Creek, the enclosure is an important archaeological site, and it is protected as part of a state park. Read more on Wikipedia
Source: en.wikipedia.org