The central Mexican city of Xochicalco was established around a.d. 670 atop a 400-foot-tall hill. At the city’s highest level, which was only accessible through three defended porticoes, stands its most important structure, the nearly square Pyramid of the Feathered Serpents.
For hundreds of years early in the first millennium a.d., Teotihuacan controlled the most powerful empire in central Mexico. At its height, the city covered some eight square miles and was home to upwards of 150,000 pe