The Great Circle Earthworks is an ancient Native American site located in Newark, Ohio. Constructed around 100 B.C. to 500 A.D., it features a large circular earthwork measuring about 1,050 feet in diameter. The site is part of a larger complex that includes other geometric earthworks, showcasing the advanced engineering skills of the Hopewell culture. The Great Circle is believed to have served ceremonial and astronomical purposes. Its design aligns with celestial events, indicating that the builders had a sophisticated understanding of astronomy. Today, the site is preserved as a historical landmark and is part of the Hopewell Culture National Historical Park.