Archeologists are opening a cave sealed for more than 30 years deep beneath a Mexican pyramid to look for clues about the mysterious collapse of one of ancient civilization's largest cities.The soaring Teotihuacan stone pyramids, now a major tourist site about an hour outside Mexico City, were discovered by the ancient Aztecs around 1500 AD, 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 700 AD.
More HERE.
