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Witness ancient brilliance in each of the Hopewell earthworks

A memorable and enriching experience

Octagon Earthworks

Newark, OH

One of the grandest remnants of the Newark Earthworks, the Octagon Earthworks is an architectural feat or astonishing precision. Its unique and somewhat mysterious shape  was built by dispersed people on a scale that required remarkable collaboration and an advanced understanding of the cosmos.

Visitor Info

125 N. 33rd St.
Newark, OH 43055

  • Park grounds: The full Octagon Earthworks site is not currently open to the public except for an observation tower and a marked path for visitors. Please follow the posted signs.


40.0519828 °N

82.4463745 °W

What you'll see

The Octagon Earthworks is made of two geometric enclosures: A large circle enclosing 20 acres, and an even larger octagon enclosing 50 acres, connected to one another by an avenue. The walls of these shapes reach eye-level, and show how the Hopewell culture had an understanding of soil science, as they only selected soil with properties that would maintain the integrity of the mounds.
Directly across from the avenue, there is a break in the circular wall where two parallel extensions originally projected outward, forming a gateway. This former gateway is covered by a large, earth and stone platform mound called the Observatory Mound.
Octagon Earthworks map

Archaeology & Artifacts

Few archaeological investigations have been performed at the Octagon Earthworks, and as a result, no known artifacts have been uncovered. Because the walls and interior spaces are relatively intact, it’s exciting to think about what future archaeological investigations will reveal about these structures and their builders.
Octagon Earthworks
Octagon Earthworks at dusk

Human Genius

The rhythm of the moon is written into the Octagon Earthworks. While itʻs not possible to say with certainty why this structure was built, the alignments of the rising and setting of the moon over its 18.6 year long cycle suggest shared beliefs.
A line drawn between the center points of the Great Circle and the Octagon Earthworks’ Observatory Circle point to where the moon rises at its southernmost point on the eastern horizon. When combined with the many precise alignments to the key moonrises and moonsets at the Octagon Earthworks, we can see that these ancient American Indians were diligent and patient sky watchers for many generations. They figured out the complicated rhythms of the sun and moon and aligned their sacred earthworks to those rhythms as a way of connecting their ceremonies with the cosmos.

Witness Ancient Brilliance

The Hopewell Ceremonial Earthworks, a UNESCO World Heritage Site, span several locations in Ohio. Each earthwork has its own marvels and wisdom to reveal, and is worthy of witnessing firsthand.