A heavy rainstorm swept through the ruins of Teotihuacán, the pre-Aztec metropolis 30 miles northeast of present-day Mexico City, in the fall of 2003. A torrent of mud and debris coursed past rows of souvenir stands at the main entrance, washing over dig sites. The city’s central courtyard’s grounds buckled and broke. Sergio Gómez, an archaeologist with Mexico’s National Institute of Anthropology and History, arrived at work one morning to find a nearly three-foot-wide sinkhole at the foot of the Temple of the Plumed Serpent, in Teotihuacán’s southeast quadrant.
“My first thought was, ‘What am I looking at exactly?'” Gómez recently informed me. “The second question was, ‘How are we going to fix this?'”
Gómez is wiry and small, with prominent cheekbones, nicotine-stained fingers, and a dense black hair helmet that adds a couple of inches to his height. He has spent the past three decades—nearly his entire professional career—in and around Teotihuacán, which was once a cosmopolitan center of the Mesoamerican world. He likes to say that there are few living humans who know the place as well as he does.
And, in his opinion, there was nothing beneath the Temple of the Plumed Serpent other than dirt, fossils, and rock. Gómez reached into his truck for a flashlight and pointed it into the sinkhole. Nothing but darkness. So he wrapped a heavy rope around his waist and descended into the murk, with several colleagues holding onto the other end.
Gómez was discovered dead in the middle of what appeared to be a man-made tunnel. “I could see some of the ceiling,” he explained, “but the tunnel was blocked in both directions by these enormous stones.”
The major monuments in Teotihuacán (pronounced tay-oh-tee-wah-KAHN) were arranged on a north-south axis, with the so-called “Avenue of the Dead” connecting the largest structure, the Temple of the Sun, with the Ciudadela, the southeasterly courtyard that housed the Temple of the Plumed Serpent. Gómez was aware that archaeologists had discovered a narrow tunnel beneath the Temple of the Sun. He reasoned that he was now in a mirror tunnel leading to a subterranean chamber beneath the Temple of the Plumed Serpent. If he was correct, it would be a stunning find—the kind of achievement that can make or break a career.
“The problem was,” he explained, “you couldn’t just jump in and start tearing up the earth.” You must have a clear hypothesis and obtain approval.”
Gómez got to work on his plans. He erected a tent over the sinkhole to shield it from the prying eyes of the hundreds of thousands of tourists who visit Teotihuacán each year, and arranged for the delivery of a lawnmower-sized, high-resolution, ground-penetrating radar device with the assistance of the National Institute of Anthropology and History. Beginning in early 2004, he and a hand-picked team of 20 archaeologists and workers scanned the earth beneath the Ciudadela, returning every afternoon to upload the results to Gómez’s computers. The digital map was finished by 2005.
The tunnel ran approximately 330 feet from the Ciudadela to the center of the Temple of the Plumed Serpent, as Gómez had suspected. The hole that had appeared during the 2003 storms was not the actual entrance; it was a few yards away and had apparently been purposefully sealed with large boulders nearly 2,000 years before. Whatever was inside that tunnel, Gómez reasoned, was meant to remain hidden forever.
Teotihuacán has long stood as the greatest of Mesoamerican mysteries: the site of a colossal and influential culture about which frustratingly little is understood, from the conditions of its rise to the circumstances of its collapse to its actual name. Teotihuacán translates as “the place where men become gods” in Nahuatl, the language of the Aztecs, who likely found the ruins of the deserted city sometime in the 1300s, centuries after its abandonment, and concluded that a powerful ur-culture—an ancestor of theirs—must have once resided in its vast temples.
The city lies in a basin at the southernmost edge of the Mexican Plateau, an undulating landmass that forms the spine of modern-day Mexico. Inside the basin the climate is mild, the land riven by streams and rivers—ideal conditions for farming and raising livestock.
Teotihuacán itself was likely settled as early as 400 B.C., but it was only around A.D. 100, an era of robust population growth and increased urbanization in Mesoamerica, that the metropolis as we know it, with its wide boulevards and monumental pyramids, was built. Some historians have theorized that its founders were refugees driven north by the eruption of a volcano. Others have speculated that they were Totonacs, a tribe from the east.
Whatever the case, the Teotihuacanos, as they are now known, proved themselves to be skilled urban planners. They built stone-sided canals to reroute the San Juan River directly under the Avenue of the Dead, and set about constructing the pyramids that would form the city’s core: the Temple of the Plumed Serpent, the even larger 147-foot-tall Temple of the Moon and the bulky, sky-obscuring 213-foot-tall Temple of the Sun.
Clemency Coggins, a professor emerita of archaeology and art history at Boston University, has suggested that the city was designed as a physical manifestation of its founders’ creation myth. “Not only was Teotihuacán laid out in a measured rectangular grid, but the pattern was oriented to the movement of the sun, which was born there,” Coggins has written. She is far from the only historian to see the city as large-scale metaphor. Michael Coe, an archaeologist at Yale, argued in the 1980s that individual structures might be representations of the emergence of humankind out of a vast and tumultuous sea. (As is in Genesis, Mesoamericans of the time are thought to have envisioned the world as being born from complete darkness, in this case aqueous.) Consider the Temple of the Plumed Serpent, Coe suggested—the same temple that hid Sergio Gómez’s tunnel. The structure’s facade was splashed with what Coggins called “marine motifs”: shells and what appear to be waves. Coe wrote that the temple represents the “initial creation of the universe from a watery void.”