Octagon Earthworks

This 120-acre tract of earthworks containing three structures in geometric shapes, and known collectively as the Octagon Earthworks, is sited south of Ohio state route 16 in Newark on the grounds of Moundbuilders County Club. The largest structure, the Octagon, encloses 50 acres within its eight walls. There are two accompanying circles—Observatory Circle and a much smaller circle—that complete the surviving complex. The Octagon is aligned with lunar cycles of moonrises and moonsets. The alignment, symmetry and scale of the Octagon would make it a monumental construction on its own, yet it was just one structure in a greater complex. The smaller Observatory Circle encompasses 20 acres and is connected by a wide pathway to the Octagon. The scale and measurements of the earthworks were standardized. The Observatory Circle, with a diameter of 1,054 feet, can serve as the standard by which to measure the greater earthworks complex. The distance between the center of the Observatory Circle to the center of the Great Circle is six times the diameter of Observatory Circle. The distance from the center of the Octagon Earthworks to the center of the Wright Square is also six times the diameter of the Observatory Circle, illustrating the command of mathematics and engineering that the Hopewell possessed.

The Octagon Complex was used as a National Guard encampment called Camp McKinley from 1892 to1908. The city of Newark then leased the site to the Moundbuilders Country Club. Ownership of the land has passed to the Ohio History Connection, but the lease to the Mound Builders County Club has continued for more than a century. The Octagon complex remains a part of an active golf course, limiting access to the earthworks. The Octagon can be viewed from north 30th Street, the Octagon and small circle from Parkview Road, and the Observatory Circle from Moundview Avenue. There is public access to Observatory Mound behind the Licking Memorial Hospital.

Image 1: Detail view of a map showing the Octagon and Observatory Circle.

Image 2: Postcard of the Moundbuilders Country Club as it appeared around 1914.

Image 3: Panoramic photograph of the Camp McKinley military encampment at the Octagon in 1904.