Digging Up Mysteries
A sinkhole opened where thousands walked daily, but few noticed its deeper secret. What followed was years of patient digging, revealing treasures, tunnels, and something stranger still—liquid mercury shimmering beneath the Earth.
Ancient Teotihuacan
Deep in Mexico's central highlands, about thirty miles northeast of modern Mexico City, lies one of the most enigmatic archaeological sites in the Americas. Teotihuacan flourished between 100 BCE and 750 CE, becoming the largest urban center in the pre-Columbian Western Hemisphere.
City Layout
The ancient architects designed Teotihuacan around a massive two-mile-long ceremonial boulevard called the Avenue of the Dead. Three colossal pyramids dominated the skyline: the 213-foot Pyramid of the Sun, the 140-foot Pyramid of the Moon, and the ornately decorated Temple of the Feathered Serpent.
Feathered Serpent
Also known as the Pyramid of Quetzalcoatl, the Temple of the Feathered Serpent is the third-largest structure in Teotihuacan, measuring 213 feet by 213 feet at its base. Its facade features hundreds of carved stone serpent heads with feathered bodies, representing the powerful deity Quetzalcoatl.
Rainstorm Revelation
In October 2003, after days of heavy rainfall, archaeologist Sergio Gomez Chavez noticed a nearly three-foot-wide sinkhole that had opened near the foot of the Temple. Determined to investigate, Gomez tied a rope around his waist and had colleagues lower him into the mysterious cavity.
Sergio Gomez
Sergio Gomez, an archaeologist with Mexico's National Institute of Anthropology and History (INAH), became the lead researcher of what would become one of Mexico's most significant archaeological discoveries. His methodical approach and unwavering dedication would drive a multi-decade excavation project.
ARQUEÓLOGO SERGIO GOMEZ portugues by instituto Maya Hunabku
Initial Descent
Descending into the darkness, Gomez found himself in a cylindrical shaft leading to an ancient man-made tunnel blocked by massive stones in both directions. The underground passage appeared to be an ancient construction, similar to a narrow tunnel previously spotted beneath the Pyramid of the Sun.
Digging deep into Teotihuacan's mystery by AFP News Agency
Government Permission
After six years of preliminary studies and bureaucratic processes, the Mexican government granted this individual official permission to excavate in 2009. He installed a protective tent over the sinkhole to shield the work from thousands of daily tourists visiting Teotihuacan.
Robot unlocks ancient Mexico mysteries by Al Jazeera English
Tunnel Mapping
It is reported that the excavation team utilized innovative 3D laser scanning technology to map the tunnel's interior prior to the commencement of physical excavation. Hundreds of thousands of laser points bounced off tunnel walls, creating detailed digital maps.
David Monniaux, Wikimedia Commons
Manual Excavation
The painstaking excavation process proceeded at an incredibly slow pace, with workers advancing only inches at a time using hand tools and spades. Nearly 1,000 tons of earth, rocks, and debris were manually removed from the tunnel, which had been intentionally sealed 1,800 years ago.
Ancient Aliens: Secrets of Teotihuacan (Season 12, Episode 7) | History by HISTORY
Artifact Cache
Furthermore, archaeologists uncovered an extraordinary collection of over 50,000 artifacts. The treasure trove included jade sculptures from Guatemala, massive Caribbean seashells, obsidian blades, carved rubber balls used in Mesoamerican ball games, pyrite mirrors that crafted starlike reflections, and jaguar skeletons.
More secrets of Mexico's Teotihuacan are revealed by Tim Allman
Robot Exploration
In 2013, Gomez deployed a specially constructed remote-controlled robot named "Tlaloc II-TC" to explore the tunnel's deepest sections without risking human exposure to potential hazards. The robot, equipped with infrared cameras and sensors, navigated through narrow passages and spotted three distinct chambers at the tunnel's terminus.
Mercury Discovery
The most startling revelation came when archaeologists found large quantities of liquid mercury pooled in miniature valleys within the underground chambers. This toxic, silvery metal had been deliberately placed to create what appeared to be artificial lakes and rivers in a carefully constructed miniature landscape.
Toxicity Concerns
Upon spotting the mercury deposits, excavation protocols were immediately changed to protect workers from the metal's dangerous vapors. Team members began wearing complete protective breathing apparatus, hazmat suits, and specialized ventilation equipment. The presence of radon gas, detected simultaneously with the mercury, required additional safety measures.
FEMA/Win Henderson, Wikimedia Commons
Chemical Properties
Mercury's unique characteristics made it extraordinarily valuable in ancient Mesoamerica due to its rare liquid metallic state at room temperature and brilliant reflective surface. Its density, nearly 13.6 times that of water, allows it to flow like liquid silver while maintaining its mirror-like surface properties.
Tavo Romann, Wikimedia Commons
Production Methods
Ancient Mesoamericans extracted liquid mercury by heating cinnabar ore (mercury sulfide) in specialized furnaces, separating mercury from sulfur through controlled evaporation and condensation processes. This labor-intensive technique required sophisticated metallurgical knowledge and dedicated workshops. The red cinnabar pigment was commonly used for decorating jade objects.
Mesoamerican Mirrors
Throughout Mesoamerican cultures, mirrors held sacred power as portals between the earthly and supernatural realms. These were often fashioned from materials such as obsidian, pyrite, and mica. Tezcatlipoca, whose name translates to "Smoking Mirror," personified the spiritual connection between the physical and the spiritual realms.
James St. John, Wikimedia Commons
Underworld Symbolism
The mercury pools likely mirrored sacred rivers flowing through Mictlan, the Mesoamerican underworld where souls journeyed after death. Unlike the River Styx in Greek mythology, Mesoamerican death rivers were conceptualized as shimmering, reflective waterways that carried spiritual essence between worlds.
AlejandroLinaresGarcia, Wikimedia Commons
Royal Tomb
Archaeologists theorize that the mercury chambers may indicate proximity to Teotihuacan's first discovered royal burial site. This potentially contains remains of the city's mysterious rulers. No confirmed royal tombs have ever been found at Teotihuacan, unlike other Mesoamerican sites.
Dating Analysis
Radiocarbon dating of organic materials spotted within the tunnel confirms that the chambers were sealed during Teotihuacan's Early Classic period, which was around 200–250 CE. Pottery sherds, plant seeds, and fragments of possible human skin discovered alongside the mercury provide chronological markers.
Comparative Sites
Previous mercury discoveries at Mesoamerican archaeological sites include trace amounts at two Maya locations and one Olmec site, but none approached the quantities found beneath Teotihuacan's pyramid. At Lamanai in Belize, archaeologists found small mercury deposits in elite tombs, while Olmec sites contained mercury-treated jade artifacts.
Martin Falbisoner, Wikimedia Commons
Preservation Conditions
The sealed tunnel's unique microenvironment crafted exceptional preservation conditions through consistently high humidity levels and oxygen deprivation that prevented normal decay processes. Ancient plant seeds remained viable after nearly two millennia, while organic materials like animal fur, wooden artifacts, and textile fragments survived intact.
The everyday objects of Teotihuacan by Boston University
Scientific Testing
Laboratory analysis of the mercury samples revealed chemical signatures consistent with cinnabar deposits found in central Mexican mountain regions, indicating local sourcing rather than long-distance trade networks. Apparently, additional testing on surrounding soil samples found mercury contamination patterns.
Global Significance
All in all, this discovery represents the largest quantity of liquid mercury ever found at any archaeological site worldwide, surpassing even China's famous Qin Shi Huang mausoleum, where mercury rivers were described in historical texts but never confirmed archaeologically. International archaeologists recognize Teotihuacan's mercury pools as evidence of sophisticated chemical knowledge.
damian entwistle, Wikimedia Commons
Ongoing Excavation
Current excavation work continues with extreme caution due to mercury exposure risks and the irreplaceable nature of undisturbed archaeological contexts. Researchers employ micro-excavation techniques using dental tools and brushes to carefully expose artifacts without disturbing their precise positioning.
NUEVO ROBOT RECORRERÁ ÚLTIMO TRAMO DEL TÚNEL DE TEOTIHUACAN by INAH TV
