I started this last week with a visit to the archaeological site of Plaza de las Columnas, currently being excavated by Dr. Nawa Sugiyama. This site is part of Teotihuacan, and has produced some spectacular finds linking the Maya and Teotihuacan.
(Here’s a video link to a presentation in Spanish she and her father, Dr. Saburo Sugiyama, gave here in Mexico City, about these recent discoveries.)
When we arrived at Dr. Sugiyama’s dig, she had us put on hard helmets and walk– or really, crawl– through a tunnel she and her team have dug under a pyramid. It was hard to avoid knocking off my helmet (it did fall off once), but in the process I was reminded of the tunnels that were dug by the Teotihuacanos, underneath two of the main pyramids at Teotihuacan: The Pyramid of the Sun and the Feathered Serpent Pyramid.
A Tunnel Under the Pyramid of the Sun?
In 1971, Mexican archaeologists came across a depression in front of the Pyramid of the Sun. Upon further investigation, they realized that it was actually a man-made staircase that led down into a cave-tunnel– a naturally formed cave that was the result of a lava flow from millions of years ago. This 103-meter long tunnel was reinforced by the people of Teotihuacan with mud and basalt slabs, some of which are still in place today. Archaeologist Rene Millon has suggested that some pottery fragments and mirrors found inside the cave could date to the Late Tlamimilolpa phase of Teotihuacan, which corresponds to 250-450 AD.
Did the Teotihuacanos know about this cave when the Pyramid of the Sun was built between 1-150 AD? The answer is most likely yes. The tunnel itself begins at the front of the pyramid and runs to the exact center of the structure, ending under the pyramid’s highest point. This suggests that the Teotihuacanos not only knew about the cave, but orchestrated the construction of the pyramid and the modifications of the tunnel so that the two would coincide.

But why would they do this? Scholar Doris Heyden (1975) suggests that this cave-tunnel might have been a pilgrimage destination, a shrine to which people would travel in order to worship. It has been difficult to find concrete evidence of this fact; however, shrines associated with caves were common enough in Central Mexico that this could be a likely answer.
Another Tunnel Under the Feathered Serpent Pyramid
To the south of the Pyramid of the Sun, underneath the Feathered Serpent Pyramid, lies another clue to the importance of caves at Teotihuacan. Archaeologists in recent years have uncovered yet another cave-tunnel constructed by Teotihuacanos and later closed by them as well.
How is this different from the tunnel under the Pyramid of the Sun? In many ways, this tunnel is very similar to the other tunnel. It shares a similar length, and also extends from the front of the Feathered Serpent Pyramid to just under the center of the structure. However, this pyramid appears to have a much stronger association with the levels of the Mesoamerican cosmos: upon further exploration, Mexican archaeologist Sergio Gomez Chavez has found that the tunnel correlates to the three levels of the cosmos (upper world, terrestrial plane and underworld) and has a chamber that branches into the four directions of the cosmos as well.
Various figurines were recovered from the tunnel, and archaeologists observed that the interior of the end of the tunnel was carved to represent the watery, mountainous landscape of the underworld, from which this world was born. It appears that the Teotihuacanos sealed the tunnel leading out of the cave not once, but twice, indicating that they might have returned to leave or take something at a later date.
These underworld connections tie in very clearly with the iconography of the Pyramid of the Feathered Serpent, which I explain more in detail in my online course on Teotihuacan.
Be sure to check out this 360-degree video created by Mexico’s Secretaria de Cultura. It shows you aerial views of Teotihuacan, and a live tour of the tunnel under the Pyramid of the Feathered Serpent!
