Pyramid of the Sun and Pyramid of the Moon, Teotihuacán, State of Mexico Taking a quick trip away from the Maya world and up to the Valley of Mexico puts us in the heart of Teotihuacán.

(Getty Images)| In Mexico's ancient city of Teotihuacán – a UNESCO World Heritage Site that once boasted a population of more than 125,000 people – visitors will find the Pyramid of the Sun.

From exploring Mexico's diverse cities and magic towns ... its most impressive structure is by far the Pyramid of the Sun. The largest structure of its kind in the entire Western Hemisphere ...

Archaeologists have discovered the ruins of an 800-year-old Aztec pyramid in the heart of Mexico City that could show the ancient city is at least a century older than previously thought.