Panther Intaglio Effigy Mound - Credit: Wikimedia Commons
The Panther Intaglio Effigy Mound is a ground depression in Fort Atkinson, Wisconsin. The effigy is a reverse mound: a depression in the shape of a panther or water spirit created by Native Americans before the arrival of settlers. In the mid-1800s ten of these reverse effigy mounds were found in Wisconsin, but all except this one have been destroyed. It was added to the National Register of Historic Places in 1970. Read more on Wikipedia
Source: en.wikipedia.org