Teotihuacan and the 103-Meter Tunnel Called a Ritual

In October 2003, heavy rain collapsed the ground in front of the Feathered Serpent Temple at Teotihuacan, about 40 kilometers from Mexico City. Archaeologist Sergio Gómez Chávez shone a light into the opening and saw stone walls. It was not a natural cave. Ground-penetrating radar showed a human-cut tunnel about 103 meters long, beginning 14 meters below the surface and running straight toward the temple's center, with its deepest point about 18 meters down.

The entrance had been filled with stones for nearly 1,800 years. When Mexico's National Institute of Anthropology and History, or INAH, opened the route one section at a time, the team recovered around 50,000 objects, including some 4,000 wooden pieces: sea shells, greenstone, stone figures, seeds, jaguar bones, pyrite mirrors, and mineral-coated spheres. Small pools of liquid mercury lay at the far end. Magnetite, pyrite, and hematite powder were worked into the roof and walls, reflecting torchlight. Water had once been directed into channels, and the deep chambers sat directly below the temple's center.