The OES visited the Newark Earthworks on June 11, 2001. These prehistoric Hopewell culture earthworks were once the largest set of geometric earthen enclosures in the world, encompassing more than four square miles. The earthworks date between 100 BC to 500 AD. Researchers believe that the earthworks were used as a burial place, cathedral, and astronomical observatory. People living in or near the earthworks probably benefited from the nearby Flint Ridge. Unfortunately, modern development and agriculture have destroyed most of the earthworks. There are, however, multiple sections that have survived including the Octagon Earthworks, Wright Earthworks, and the Great Circle. The Octagon Earthworks are located on a private golf course, but the Great Circle is open to the public, sitting on 15 acres. In the 1850s, the Great Circle was the site of the Licking County Fairgrounds and served variously as the county fairground, state fairground, amusement park, horse-racing venue, and military drill field into the early 1900s. The earthworks' properties were transferred to the City of Newark and the Ohio Historical Society by the 1930s. Below are photos that were taken of the Great Circle section of the mounds.