A rendering of the tunnel beneath the Pyramid of the Feathered Serpent in Teotihuacan (Image courtesy INAH)

A rendering of the tunnel beneath the Pyramid of the Feathered Serpent in Teotihuacan (image courtesy INAH)

Large quantities of liquid mercury have been discovered at one of Mexico’s most sacred pre-Columbian sites. Archaeologist Sergio Gómez told Reuters that he found the silvery poison beneath the Pyramid of the Feathered Serpent in Teotihuacan — the third largest pyramid in the ancient city. It was located within a chamber at the end of an 1,800-year-old tunnel that has already turned up thousands of artifacts, including jaguar remains and jade statues.

“It’s something that completely surprised us,” Gomez, who has been excavating the site for the past six years, said. Being extremely difficult to mine, mercury was a rarity in Mesoamerica; it has been found at only one Olmec site and two Maya ones, but never before at Teotihuacan.

It’s not the only shiny thing to have been found beneath the Teotihuacan pyramid, though. When excavators first unsealed the tunnel in 2011, they were surprised to discover its walls coated in a glittery metallic powder. While the meaning of this remains unclear, Mesoamericans revered reflective surfaces for their religious meaning. As Annabeth Headreck, a professor at the University of Denver and a scholar of Teotihuacan, told the Guardian“Mirrors were considered a way to look into the supernatural world, they were a way to divine what might happen in the future.”

Gómez now speculates the mercury may have represented an underworld river — which could be a favorable sign that nearby might lie an even greater discovery: the tomb of a king. The architect has been avidly searching for a royal burial that would shed light on how the pre-Aztec civilization that occupied the area between 100 and 700 CE (and which left no written record) functioned politically. He has previously said that the tunnel could have been used by kings to “acquire divine endowment allowing them to rule on the surface.”

While some archaeologists think early Teotihuacan was governed by more than one ruler, US archaeologist George Cowgill said Gómez might be on to something. “But it’s still very uncertain and that is what keeps everybody in suspense,” he told Reuters.

Laura C. Mallonee is a Brooklyn-based writer. She holds an M.A. in Cultural Reporting and Criticism from NYU and a B.F.A. in painting from Missouri State University. She enjoys exploring new cities and...