Archeologists in Mexico have announced an unprecedented find of at least 50,000 relics in a previously unexplored tunnel beneath a key pyramid and temple structure at Teotihuacan, the ancient ceremonial center on the outskirts of Mexico City.
Mexico's National Institute of Anthropology and History, or INAH in Spanish, said in a special symposium last week that the excavation of the tunnel may eventually lead to crucial burial chambers directly beneath the Temple of the Feathered Serpent, the third largest pyramid at Teotihuacan after the Pyramid of the Sun and the Pyramid of the Moon.
The discovery is called the most important single find of artifacts at the site in just over 100 years of its study.
The tunnel rests at the base of the Temple of the Feathered Serpent. Its entrance was first uncovered in 2003 after heavy rains exposed a small opening. Authorities now believe the tunnel was sealed by the Teotihuacano people some 1,800 years ago.
Excavators have found arrowheads, animal bones, seashells, statues, pottery, seeds, jade ornaments and obsidian stones. Amber fragments, wooden objects, and rubber balls have also been discovered in the tunnel's interior.
Anthropologists are hoping the contents of the tunnel will help historians better understand those who built the city, which is believed to have reached a population of an estimated 100,000 people at its peak, before Teotihuacan was abandoned in around 200 AD.
The Aztecs arrived at the Valley of Mexico in the early 14th century after the unknown civilization's decline, and named the city Teotihuacan — "birthplace of the gods" in Nahuatl. The Aztecs were likely influenced by the old city's magnitude, adopting architectural aspects in their future constructions in Tenochtitlan, or modern-day Mexico City.
More than 970 tons of dirt and stone have been removed in the excavation process of the tunnel, which is at least 330 feet long.
Sergio Gómez, the archeologist who is spearheading the excavation effort, said they've uncovered 18 walls scattered throughout the tunnel in a zigzag shape, reminiscent of the serpent itself, and in some areas reveal remnants of its original architects in the form of handprints left in clay.
Archeologists believe these added walls were used to seal off the tunnel on previous occasions, suggesting its builders may have been protecting a significant burial deeper into the pyramid's base.
The tunnel has three chambers at its finishing point, the contents of which are still unknown, but that may contain clues about the hierarchy of the society that built Teotihuacan.
The massive undertaking into the tunnel's interior has been titled Tlalocan: Journey to the Underworld, and the INAH reports that more than $1 million has been invested in the project since 2009.
"As we make advances in the exploration process, the offerings become more and more numerous, rich, and varied," Gomez said in a statement. He added that the archaeologists have discovered "more than 4,000 perfectly conserved wood objects, more than 15,000 seeds of different plants, and skin remnants, which may be human, and are to be subjected to analysis."
Archeologists also found four large anthropomorphic statues made of green stone, dozens of seashells from the Gulf of Mexico, jade that is believed to have been imported from Guatemala, bones, and hair belonging to large felines.
The tunnel was mapped using geo-radar imaging, laser scanners, and a small fleet of remote-control robots built by students from the National Polytechnic Institute, or IPN. Excavations are expected to continue for at least another year, INAH said.
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