New research at the Cuicuilco archaeological zone in Mexico has confirmed precise equinoctial alignments at its massive circular temple. The site, which predates the rise of Teotihuacán, features a unique truncated cone structure that researchers have now verified was used as a sophisticated astronomical instrument to track solar cycles and seasonal agricultural transitions.
The study utilized high-precision laser measurements and archeoastronomical modeling to demonstrate that the temple's main ramps and altars align perfectly with the sunrise during both the spring and autumn equinoxes. This finding highlights the advanced mathematical and astronomical knowledge of the Pre-Classic period civilizations in the Valley of Mexico, long before the arrival of the Aztecs.