My wife and ! went to Hovenweep National Monument this weekend because the equinox was at 4:28 AM on Monday. I've been using the book "Living the Sky - The Cosmos of the American Indian" by Ray A. Williamson (1984) as my "guide" to solar alignments in native American ruins in the Southwest. I am just trying to get a sense of them, and not really analyze them. Due to the distance casual observers must keep from the ruins, most alignments aren't really visible to casual park visitors, anyway. I have no experience with archaeoastronomy, and I am just trying to relate my experience. I am not making any claims regarding an alignment, but I am posing that possibility, and asking for comments. In Hovenweep, the more widely known alignments are for the winter and summer solstices. I am aware of the following equinox alignments: Hovenweep Castle - sunset Unit-Type House - sunrise Cajon - sunrise and sunset Holly - I think most references say that the petroglyph panel is a summer solstice event, but "The Grand Circle Tour" by Michael Royea says it also denotes the equinox. I don't know. I was only able to witness one location at sunset. Accompanying photos are available here. https://1drv.ms/i/s!AvBZjnVxo1n0vmvK_3tMzoXj6rR9 I don’t know how the panoramic photo will show on the screen, but you might have to click on it to open it to the full width to read all my labelling. Since the Cajon ruins sounded most promising, that's where we went on Sunday evening, just about 9 hours before equinox. Two buildings are aligned in such a way that the equinox is said to be the only time that either of them does not cast a shadow upon the other at either sunrise or sunset, alternatively due to the season. At sunset on Sunday, this wasn't exactly right, for which Williamson gives an explanation perhaps due to the Anasazi counting days between solstices rather than the exact equinox, but I did see an alignment that I have not seen mentioned in either book, or anywhere else I've looked - a shadow from the edge of the west building that evenly bisected the light beam passing thru the door of the east building and portrayed on the far wall. It was very transient, but I found it amazing because it was totally unexpected, even though the effect was dampened by a cloud layer on the horizon and light diffusion due to an obscuring bush. It came and went quickly enough that by the time I tried to take a photo (7:01 PM), the sunlight had faded even on the exterior wall. After that, the cloud layer on the horizon prevented any more solar shadows before sunset (7:27 PM, I think). What I have labelled the "shadow casting corner" wall appears to have broken down to where it is only about 3 feet high today. Its base is at a higher elevation than the ground level of the east building, so it casts a shadow further than if they were at the same level. If this wall itself was higher, its shadow would have cast a continuous vertical line thru the doorway of the east building. As it is, it cast a stepped shadow that I tried to outline on one of the photos, the step identifying the top and side of this corner. To watch this shadow inside the far wall of the east building, my own shadow partly obscured it, but back-sighting to the sun directed my eyes to this corner. I attempted yesterday to send an email to Dr. Williamson, to see if this has been recognized before, but if I don't hear from him, I don't know who else to ask. This was my first trip to Hovenweep, and spent only 8 hours there, so I am only casually familiar with the architectural features of the other buildings, so my following observations can't be trusted. With that in mind, the walls of Hovenweep structures are typically flat, with no protruding or cantilevered rocks. I found it unusual that both of these buildings had cantilevered rocks on the corners that are nearest each other, and I wonder if there is a significance or just a coincidence. And the windows at other Hovenweep ruins are typically perpendicular to the walls. The ones I've labelled as possible solstice portals are the only ones I noticed to be purposefully diagonal, and in the general directions of the solstices. I wonder if all of these features (door, portals, etc.) are original, or reconstructed, because the walls appear to have been patched and stabilized. Altogether, I have more questions than answers, but left Hovenweep having had a fun experience Bob Grant Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10