Xochicalco sits on an artificially levelled hilltop about 38 km south of Cuernavaca, commanding views in every direction. The site flourished between roughly AD 700 and 900, bridging the gap between the collapse of Teotihuacán and the rise of the Toltecs, and it shows clear influences from several different Mesoamerican cultures simultaneously. It is a UNESCO World Heritage Site.
The Pyramid of the Feathered Serpent is the centrepiece: its lower panels are carved with undulating feathered serpents, seated figures in complex headdresses, and glyphs that scholars have spent generations decoding. Below the main platform, a shaft descends into an underground chamber where — twice a year at solar zenith — a beam of sunlight falls directly down through an opening in the ceiling. The site museum at the entrance is excellent and worth an hour before climbing to the ruins.