Built by Native Americans 2,000 years ago, the Great Circle Earthworks and Octagon Earthworks in Newark are two of the eight component sites of Ohio’s Hopewell Ceremonial Earthworks, which were inscribed as the state’s first and only UNESCO World Heritage Site in 2023. These two examples of monumental landscape architecture in Newark consist of giant geometric shapes formed by low walls of earth carried and placed by human hands between 1 and 400 A.D. The Great Circle includes a fascinating museum, and a visitor center is available at the Octagon; tours are offered at both sites.