The Prehistoric Newark Earthworks

The Great Circle & Octagon Earthworks of the Hopewell Culture
(Photo of the bronze relief sculpture outside of the Interpretive Center.)

100 BC to AD 500 - Ancient cathedral - Observatory - Cemetery

The Great Circle Earthworks was built by the Hopewell culture somewhere between 100 BC and AD 500. This remarkable 2,000 year old ceremonial complex is also the largest system of interconnected prehistoric earthworks in the world. It is located in the center of what is now known as the State of Ohio.

One of the prehistoric moats encircling the massive southeast enclosure, the Great Circle. Here the perimeter wall is roughly 15 feet high as viewed from the outside. The moat is approximately seven feet deep.

At the time of the 1837-1847 surveys, the walls near the entrance of the Great Circle were measured at 16 feet high with the moat area being 13 feet deep.

At its widest point, the Great Circle spans 1,189 feet. (or nearly 400 yards wide).

Entering the Great Circle would have doubtless been quite impressive, if not awe inspiring back in 100 BC.

In the center of the Great Circle there is a low mound called Eagle Mound. Perhaps it once was a effigy mound resembling an eagle but today, it just appears to be a cluster of low mounds.

These mounds are also said to cover the remains of a large ancient structure.

These lower mounds lined each side of the broad causeways that connected the large octagon and circle enclosures.

Ceremonial and Celestial:

As an important ceremonial site to the Hopewell culture the earthworks may have also served as an astronomical calendar. Various segments of the earthwork align with the rising and setting of the moon.

In ancient times the earthworks complex covered an area of more than four square miles. Today, only three major complex segments survive.

The Great Circle Earthworks are part of the Newark Earthworks consisting of the nearby Octagon Earthworks and Wright Earthworks

The Squire and Davis Survey Map of The Newark Earthworks from 1847

Wall section of the Great Circle Earthwork at Newark

Lunar Observatory:

Researchers from Earlham Collage have determined that The Great Octagon was designed to serve as a lunar observatory. Movements of the moon can be tracked so accurately that measurements of specific lunar events are within one-half of a degree of the octagon's exact center.

This makes the Octagon Earthwork nearly twice as precise as the complex at Stonehenge.

A section of the Squire and Davis Map depicting the Octagon Earthworks.

The Octagon Earthwork encloses 50 acres. The smaller circle earthwork encloses 20 acres. The Octagon complex is large enough to hold four Roman Coliseums!

The surviving sections of The Great Circle and the Wright Earthworks.

The Wright Earthworks was obliterated by modern developments. Except for one 50 foot section of earthen wall it now sits under roadways, homes, and factories.

What Happened to the Hopewell?

Around AD500 the Hopewell culture seemed to vanish. Their unique artwork ceased as did mound building. The vast Hopewell trade network seemed to disintegrate.

Their is no evidence of war or disease. Researchers now consider that it may have been climate change.

Climate change would have driven game animals to regions with more suitable climates. It would have also seriously affected crops and other sources of food.

Under such conditions the large villages and towns of the Hopewell could no longer support themselves.

It is likely that the people dispersed. into smaller groups and moved on to better opportunities.

This is really quite similar to what happens today when a small town looses its source of livelihood.

People move on!