06/07/2026.
It's been generally assumed that the East Corridor coming from the easternmost entrance to the Octagon headed, well, east. I want to take a closer look at that, along with another "east" feature of the Newark Earthworks.
Here is the eastern corridor from the Squier and Davis map.
That definitely shows an eastern path, though it does seem to have a slight northern cant to it. Note that the curve at the right shows a curve through a gap where the second terrace (a glacial river flood feature) drops down to the first terrace.
The map from the Salisbury brothers is more detailed. Here we see a straight line, a well-defined indentation (gap) between the two terraces, and here the line really does look east-west.
If you ever go on one of Jeff Gill's "Remnant Tours" of Newark, he takes you to the spot that he identifies as that gap, the site of a brick alley-way that rises west from N. Fulton Avenue. Here he is pointing it out.
Jeff notes the age of those bricks (from the early days of Newark) and how they have held up so well, almost as if they had originally been laid down on top of the well-compacted surface from thousands of people who had walked that path towards the Octagon. It also made sense from the point of view that such a path leading to the Octagon would be aligned with the equinoxes in a ceremonial fashion.
However, there was always something that bothered me about that location for the gap: with LiDAR we can see exactly where it is, and the straight line from the easternmost entrance of the Octagon to that gap. Here is how the gap shows up on LiDAR:
And this is the line that runs from the easternmost entrance of the Octagon to that gap:
As you can see, it has a slightly northerly rotation of about 1.3°, which tends to agree with Squier & Davis and disagree with the Salisburys. And this bothers me. Were the Indigineous Peoples of the Hopewell Culture incapable of figuring out due east? Did Jeff Gill somehow mistake a natural feature for the east end of the Corridor, and misidentify it as the gap? Or is there something else going on here?
As you look at this, maybe the answer is obvious to you. But it only became obvious to me quite recently. And as far as I can tell, I've not seen it pointed out in any of the literature I've looked at.
How about we draw a line from the center of the Octagon to the gap?
Bingo.
[The red "X" identfies the center of the Octagon by drawing lines from the corners of the square that defines it. The purple line runs due east from there.]
I think this makes two things very clear. First, the Indigenous Peoples knew exactly how to find east, and any ceremonial importance related to walking up the the terrace at that location was focused on the center of the Octagon. Second, this absolutely strengthens Jeff Gill's identification of that alley-way as the eastern entrance gap to the East Corridor.
This next picture encapsulates the East Corridor.
It incorporates the center of the Octagon (red "X") and the line (purple) due east from it to the gap. It also incorporates the direct line from the easternmost entrance of the Octagon to the gap. And finally, it overlays (green) the East Corridor on it all.
So, next time you go on a "Remnants Tour", as you get to the top of the brick ramp, you can think about how, if you look due west, you're looking towards the exact center of the Octagon. But if you were to head down the path of the corridor, you would have to make a small diversion slightly to your left (about 2 steps to the left for every 100 steps forward).
East and the Opening of the Great Circle
As long as I am gazing towards the east, I'd also like to take a look at the Great Circle. In Hively & Horn's first paper, they identified the line from the center of the Great Circle through the center of its opening as pointing to the minimum northern extreme (Hively & Horn 1982: S15). The deviation from that, though, was fairly large (0.9°) and they have backed off that claim, instead claiming that, due to the irregularity of the northwest side of the circle, its center is too uncertain.
That said, Jeff Gill makes a strong case that the opening aligns with the sunrise cross-quarters in May and August (near the 5th of those months). He notes that the Alligator Mound is aligned with the same axis (though facing the opposite direction for sunsets). The cross-quarters are often important dates for planting and harvesting. For my part, I think that the center of the Great Circle given by the 80% that is not distorted provides a reasonable candidate for that center, so I agree with Jeff. See Just How Great is the Great Circle?. However, one point against it asks why such a solar alignment would be part of a lunar complex like the Newark Earthworks? I may have noticed a connection.
Looking east from the center of the Great Circle is a hilltop on the horizon. (This is visible even with the walls of the Great Circle there—Eagle Mound rises enough to be level with the tops of the walls.) This hilltop emerges from a dip through the middle of a nearer set of hills.
While I have not looked at it (trees), the farther hill, at 3.6 miles away, would probably show up differently than the nearer 2.5 mile gap. Here I show the topography due east from the Great Circle. An azimuth of 90° is due east. Elevations are color-coded. However, for the Great Circle I've overlaid a properly-size relief-map. You should be able to see how the view passes through the gap to catch the hilltop behind.
Next we can look at the opening. We know that, at the equinox, the sun rises in the east towards the hilltop. What happens as the year progresses? On this relief-map of the Great Circle, I've shown the direction of the sunrises from the Spring Equinox as the year progresses towards the Summer Solstice. (Some days are omitted due to space constraints.)
Notice anything? Let me highlight one thing in particular.
The size of the opening covers one month, one lunation, approximately 29-30 sunrises. Not only that, but it is oriented such that the first sunrise framed by the opening occurs one month, that is, one lunation after the Spring Equinox. That means that, among other things, whatever phase the moon was in at the Equinox (due east), it will be in the same phase when the sun rises at the right side of the opening, and then that same phase again when the sun rises at the left side of the opening. Not only that, but spanning a month in this fashion is what makes the center of the opening align with the cross-quarters. It can serve a dual purpose.
Here is another idea about how this could be used: part of a lunisolar calendar.
Native cultures had all sorts of ways to keep track of time. Leona Cope collected a large variety of the sorts of calendars that were used (Cope 1919). In some cases, the months would only be named as they occurred (though with callbacks to previous years). But in some cases, neighboring tribes could not even agree on which month it was because carefully keeping track was not important to them.
Much of that happened because while a seasonal year is 365.25 days, a lunar year, of either 12 or 13 months (each month being a lunation), would last either 354 days or 384 days. The process of determining whether a year should have 12 or 13 months is called "intercalation". Basically, every 19 years needs to have 12 years with 12 months and 7 years with 13 months (with even then small corrections needed over the long haul). The Jewish Calendar has a fixed sequence of how to do it: years 3, 6, 8, 11, 14, 17, and 19 of the cycle have 13 months. (For a more detailed look, Wikipedia: Hebrew Calendar.)
For native tribes, new years often started on the first appearance of a new moon after, for instance, the Spring Equinox or Winter Solstice, though occassionally a full moon was also used.
Cope also has an extensive list of what the various tribes called their months (moons). Oddly enough, for any tribe, such a list usually included either 12 months or 13 months—no extra intercalation month. I don't know if this means that they didn't do intercalation, or maybe instead the ethnographers involved really didn't know that much about how to reconcile lunar and solar years.
For less sophisticated tribes, intercalation was probably done just by noting that the frogs were croaking and therefore it is now the frog-croaking month. If a naming convention got out of sequence, they would just fix it as it came. More sophisticated tribes would use the astronomical observations I noted above. It would have been pretty easy to figure out that, if the new year (e.g., first new moon after equinox) occurred within 11 days of the equinox, then there would be 13 months that year. They would then have to figure out how they would add that month, and what to call it. (In the Jewish Calendar, one of the months is called "Adar". For a 13th month, that is "Adar II".)
For the Akenabi, a tribe in Maine (Vetromile 1866: 81-82), their new year started with the new moon at the Winter Solstice. They would, at that time, determine if that year required 13 months. If so, they would add the month of Abonamwikizoos at mid-summer (near the Summer Solstice). Abonamwikizoos means "let this moon go", since on the years with only 12 months, this is the month that would be let go (omitted).
Anyways, it strikes me that the month-long sunrise opening in the Great Circle would be a great way to determine if a year needed a 13th month, assuming the new year started at the Spring Equinox. If a post were put in the ground at the right location (11 days from the right side of the opening), if the new moon arrived before the sun rose there, it was time for a 13 month, maybe even added at the Fall Equinox.
In conclusion, east shows up two important ways in the Newark Earthwork in ways that may not have been fully appreciated.
References:
Cope 1919
Calendars of the Indians North of Mexico, by Leona Cope. Vol. 16. University of California Press (1919).
Hively/Horn 1982
Geometry and Astronomy in Prehistoric Ohio, by Ray Hively and Robert Horn. Archaeoastronomy, No. 4 (1982).
Vetromile 1866)
The Abnakis and Their History: Or, Historical Notices on the Aborigines of Acadia. by Eugener Vetromile. New York: JB Kirker (1866).