Portsmouth Earthworks

Portsmouth Earthworks - Credit: Wikimedia Commons

The Portsmouth Earthworks are a large prehistoric mound complex constructed by the Native American Adena and Ohio Hopewell cultures of eastern North America (100 BCE to 500 CE). The site was one of the largest earthwork ceremonial centers constructed by the Hopewell and is located at the confluence of the Scioto and Ohio Rivers, in present-day Ohio. Read more on Wikipedia

type: ancient site
date from: 100 BCE

Source: en.wikipedia.org