Archaeologists lowered the remote-controlled, camera-equipped vehicle into the 12-foot-wide (4-meter) corridor and sent wheeling through it to see if it was safe for researchers to enter. The one-foot (30-cm) wide robot was called “Tlaloque 1” after the Aztec rain god.
The grainy footage shot by the robot was presented Wednesday by Mexico’s National Institute of Anthropology and History. It shows a narrow, open space left after the tunnel was intentionally closed off between A.D. 200 and 250 and filled with debris nearly to the roof.
Archaeologist Sergio Gomez says the footage showed the arched-roof tunnel was an example of sophisticated work by the ancient inhabitants of Teotihuacan, which is located just north of modern Mexico City.
“All of the passage, more than 100 meters (yards) long was excavated in the rock perfectly, and in some places you can even see the marks of the tools the people of Teotihuacan used to make it,” said Gomez.
Well-worked blocks and a smoothly-arched ceiling showed the tunnel was not natural, but rather a man-made structure that researchers believe lead to possible burial chambers.