Ancient Earthworks of Eastern North America
Newark Octagon Work
, Newark, Ohio

Octagon Earthworks State Memorial is currently leased to a golf club.

Newark Octagon, Newark Earthworks, Newark, Ohio

Newark Octagon, Newark Earthworks, Newark, Ohio

Newark Octagon Squier survey map

One of the most significant traces of ancient civilization in Eastern North America is the
complex array of geometric works arrayed on the earth, the greatest concentration of which covered
several square miles at Newark, Ohio. The Newark Octagon, the most northwestern of the earthworks
at Newark is the largest of all geometric earthworks. The contiguous earthwork of Observatory Mound,
Observatory Circle, the parallel embankments, and the Octagon combine to extend 2,898 feet.

Newark Octagon

Ancient Monuments Placemarks   -   Newark Octagon   -   Newark Circle   kmz files with map overlays.

Newark Octagon

Above. One of the Newark Octagon embankments and an opening mound in the far left. Each of the eight
vertices has a mound. Below. A surviving small circle, adjacent southeast of the Octagon, is now a golf green.

Newark Octagon

Newark Octagon Circle and Observatory Mound
Above and below. The arcs of Observatory Circle viewed from Observatory Mound,
above from near the mound center, and below from the southeast end of linear Observatory Mound.

Newark Observatory Circle viewed from Observatory Mound

Observatory Circle

Above. From near Observatory Circle's center, viewing the parallels and a mound in the Octagon.
Below. The Octagon from the mound seen above, with Dr. Bradley Lepper leading a site tour.

Dr. Bradley Lepper provides site interpretation

Excerpts from my 2001 paper Possible Geodetic Properties and Relationships of
Some Monumental Earthworks in the Middle Ohio Valley, A Preliminary Inquiry

The relationships between Newark Earthworks and Marietta Square and the orientations and relationships of the various monuments of Newark Earthworks offer the best evidence of knowledge and practice of geodesy. The Newark Octagon and Marietta Square ratio of arc distance to longitude difference, the azimuth of the Newark Octagon, and the bearings between Newark Circle and the Octagon Circle infer precise understanding of the mathematical ratio of latitude to longitude. The precise commensuration of the Newark to Marietta arc distance and their longitude difference with the SO module (earth’s angular orbital motion per day) infers a precise understanding of astronomic constants and the scale of the earth. The redundancy of expression of the same relationships makes it very difficult to discount the relationships as coincidental. ... The fact that the largest of the monuments express these geodetic relationships also argues against coincidence. Given the distances involved, creating the relationships between the Middle Ohio monuments could have been accomplished using direct surveying and mathematics, and thus does not necessarily infer an astronomical method of the determination of longitude. If the Newark to Fort Center relationships are intentional, use of an astronomical method for determination of longitude is also inferred.

I conclude that the builders of the Middle Ohio earthworks understood aspects of geodesy, including accurate astronomical knowledge, knowledge of the scale and shape of the earth, knowledge of their location on the earth, and how to place find and point position.

The alignment of the Octagon earthwork nearly corresponds to the northerly lunar major extrema rise/set azimuth. According to Thomas (1894), the Octagon's azimuth is 52.15° E. of N. Further discussion of possible reasons for the orientation of the Octagon is found in the Temporal Epoch Calculations page.

Newark Octagon to Marietta Capitolium Mound, arc distance = CIR / 365.0
Newark Octagon to Marietta Capitolium Mound, longitude difference = CIR / 365.0
Newark Octagon to Marietta Quadranau Mound, arc distance = CIR / 366.0
Lunar orbits per rotation = 0.036501
Lunar orbits per day = 0.036601
Newark Observatory Mound to Newark Octagon Center = 0.000100 radians
Newark Observatory Circle to Fort Center Circle = 0.0365016 CIR
The great circles at Newark align to Marietta Earthworks.

MORE: Newark Archaeogeodesy
Assessing Evidence of Geospatial Intelligence in the Americas

The Great Circle Earthwork Photo Gallery

Site Coordinates
Code Location Latitude Longitude Source
fcci Fort Center Circle 26.9546593 -81.1656965 map 1:24,000
fcmo Fort Center Mound 26.955034 -81.1626328 map 1:24,000
nocc Newark Observatory Circle 40.05207671 -82.44861007 GPS derived 3
noom Newark Observatory Mound 40.05113889 -82.45013889 GPS 5m
nocp Newark Octagon Center 40.05469583 -82.4442625 GPS derived 9
noa Newark Octagon Entrance 40.05345556 -82.44632222 GPS derived 4
nocg Observatory Circle Gateway 40.05297222 -82.447125 GPS derived 2
nopne Octagon Parallel NE 40.05338889 -82.44622222 GPS 5m
nopnw Octagon Parallel NW 40.05355555 -82.44638889 GPS 5m
nopsw Octagon Parallel SE 40.05308333 -82.44722222 GPS 4m
nopse Octagon Parallel SW 40.05286111 -82.44702778 GPS 5m
nosc Octagon Small Circle 40.0525 -82.44325 GPS 2m
nof Octagon Vertex F 40.05697222 -82.44394444 GPS 3m
nob Octagon Vertex B 40.05238889 -82.44463889 GPS 4m
noc Octagon Vertex C 40.05308333 -82.44263889 GPS 3m
nod Octagon Vertex D 40.05441667 -82.44119444 GPS 5m
noe Octagon Vertex E 40.05597222 -82.44219444 GPS 5m
nog Octagon Vertex G 40.05630556 -82.44588889 GPS 2m
noh Octagon Vertex H 40.05497222 -82.44727778 GPS 3m

Sources and Bibliography

Hively, Ray, and Robert Horn 1982 Geometry and Astronomy in Prehistoric Ohio. Archaeoastronomy 4:S83-S20.

Marshall, James A. 1987 An Atlas of American Indian Geometry. Ohio Archaeologist 37(2):36-48.

Mills, William C. 1914 Archaeological Atlas of Ohio. The Ohio State Achaeological and Historical Society.

Squier, Ephriam G. and Edwin H. Davis 1847 Ancient Monuments of the Mississippi Valley. Smithsonian Institution, Washington, D. C.

Thomas, Cyrus 1894 Report on the Mound Explorations of the Bureau of Ethnology. Twelft Annual Report of the Bureau of Ethnology. Washington.

Woodward, Susan L. and Jerry N. McDonald 1986 Indian Mounds of the Middle Ohio Valley. McDonald and Woodward, Blacksburg Virginia.

©2006 by James Q. Jacobs.  All Rights Reserved.  Permissions and Contact.
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