Archaeologists have uncovered a hidden tunnel under a popular and massive pyramid in the ancient city of Teotihuacán, northeast of Mexico City.
The tunnel was found under the Pyramid of the Moon, the second-largest structure in the ancient city, according to the International Business Times. The archaeologists who discovered it believe that it mirrors the Teotihuacans’ great monuments and may represent the underworld in the belief system of the pre-Colombian, 2,000-year-old civilization that built it.
The tunnel is long, extending from the central square known as the Plaza de la Luna to the nearby pyramid. It is about 33 feet (10 meters) deep and is similar to other tunnels that have been discovered recently, like the tunnel that was found under the Temple of the Plumed Serpent.
While no one has been able to go inside the tunnel yet, the discovery was made through a method known as electrical resistivity tomography, which creates subterranean images. A team of archaeologists from Mexico’s National Institute of Anthropology and History was using the technique as part of their conservation efforts for the central square when they stumbled upon the tunnel.
It is unclear what the tunnel may have been used for, and archaeologists plan to do more research to determine its purpose and whether or not it contains more artifacts.