Today we visited a very interesting site in Mexico City.

Cuicuilco is one of the oldest sites in the Valley of Mexico and was located on the southern shore of Lake Texcoco.

The highlight of Cuicuilco is a circular pyramid.

The ramp of the pyramid is aligned with the rising of the sun on the autumnal and vernal equinox. I had thought of making the title of this post Autumnal Equinox II, as a follow up to a post that I wrote one year ago.

It was an interesting coincidence that we visited this site on the day of the autumnal equinox.

This morning, the sun would have risen directly above the top of the pyramid. Of course, I would have had to have moved to the right a bit and look straight up the ramp.

There is debate among scholars as to whether the pyramid was used as a solar observatory in addition to a religious center. The equinox alignment may have been more chance than intentional.

This view of the backside of the pyramid shows the stepped construction. The pyramid is mainly constructed with basalt stones.

The pyramid had different phases of construction. The area was first occupied in about 600-800 BC and the construction of the pyramid was probably started soon after.

At the greatest height the pyramid was estimated to be about 130-140 feet tall and it is 260 feet in diameter. Today, the pyramid is only 90 feet high, but the reduction comes from two sources. First, there was most likely an additional structure on top, and second the lower part of the pyramid was covered by a lava flow.

The top of the pyramid has a large flat area and one theory is that their would have been a large number of people worshiping on top of the pyramid. The name Cuicuilco is thought to mean ‘Place of Prayer’.

In this view we see a large circular pit in the center of the top, and a small rise in the background.

My theory is that they would have had a standing stone or other marker on top of the rise that would mark the same axis as the pyramid ramp. The equinox could then be observed with the sun rising above the marker.

The marker would have been able to be observed by looking up the ramp toward the sun, or from the altar in the circular pit below.

Down inside of the circular pit you can see the remains of several altars. These are the remains of older altars. The most recent one was mostly destroyed. They have found multiple altars built on top of each other which is consistent with other pyramids found in Mexico. The older ones were made of pressed dirt and the more recent ones of stone.

Here we see a corridor near the top of the pyramid. It leads from the pyramid ramp to pit in the center where the altar was. Most likely the priests would use this path to go to the altar while the worshipers would continue up the ramp to the top of they pyramid.

The city of Cuicuilco was abandoned in about 150 – 200 AD when lava flows from the volcano Xitle forced the people to flee. They most likely joined the Teotihuacan culture to the north. You can read about Teotihuacan in my previous post: The Piramides.

There is evidence that worship continued at Cuicuilco. The site may have become a pilgrimage site where people would come to worship the fire god Huehuetéotl.

In the small museum at the site there is an artists rendering of what the pyramid may have looked like after the destruction of Cuicuilco. This would be the way it looked when it was a pilgrimage site. In the image you can see the tongues of lava encroaching on the pyramid.

I want to learn more about this site, but I could only find basic information in English.

Hopefully in the next week I will also share pictures from Churubusco. Do you know what happened there?

Steven