2008-07-04 08:01:32 GMT 2008-07-04 16:01:32 (Beijing Time) Xinhua English
BEIJING, July 4 (Xinhuanet) -- Archaeologists are reopening a cave beneath a Mexican pyramid that has been sealed for more than 30 years to look for clues about the puzzling collapse of one of ancient civilization's largest cities.
The soaring Teotihuacan stone pyramids are a major tourist site about an hour outside Mexico City. They were discovered by the ancient Aztecs around 1500, not long before the arrival of Spanish explorers to Mexico.
But little is known about the civilization that built the immense city, with its ceremonial architecture and geometric temples, and then torched and abandoned it around the year 700.
Archaeologists are now revisiting a cave system that is buried 20 feet (6 meters) beneath the towering Pyramid of the Sun and extends into a tunnel stretching for 295 feet (90 meters) with a height of 8 feet (2.4 meters).
They say new excavations could be the key to unlocking information about the sacred rituals of the people who inhabited the city, later dubbed "The Place Where Men Become Gods" by the Aztecs, who believed it was a divine site.
"We think it had a ritual purpose. Offerings were placed at the very end of the tunnel as part of the pyramid's construction process," Mexican archaeologist Alejandro Sarabia told Reuters. "We want to find out why the Teotihuacan people sealed it and when."
Sarabia said the tunnel was first discovered in the early 1970s but it was closed soon afterward, and most of the information about it was lost when the archaeologist who found it died.
Teotihuacan is Mexico's oldest major archaeological site, and during its heyday in A.D. 500, the city was home to 200,000 people, rivaling the size of ancient Rome at that time, according to archaeologists.