Xochicalco, meaning 'House of Flowers', developed between 650 and 900 AD on the top of a set of hills 38 km southwest of modern day Cuernavaca in the Morelos valley. There are substantial ruins, a museum and some excellent views of the valley. Xochicalco is a UNESCO World Heritage Site.
Xochicalco was founded in about 650 AD by the Olmeca-Xicallanca. At some point around AD 900 the city was burned and destroyed.
The Temple of the Feathered Serpent was restored by Mexican archaeologist Leopoldo Batres in 1910 and major archaeological excavations and further restorations continued from the 1940s to the 1960s. In 1988 a large-scale program of excavation of monumental architecture was initiated by the INAH.
Flora and fauna
Xochicalco is about 45 mins by Taxi from Cuernavaca with the Cuernavaca Airport halfway between the two. Pullman de Morelos allegedly runs a bus service direct to Xochicalco from Mexico City. They definitely run a bus service direct from their station in Cuernavaca, located on the corner of Mariano Abasolo and Netzahualcoyotl, just south of the Parque Jardin Revolucion (Sept 2018: direct bus only on weekends at 1000 and 1100; however, if you take the bus to the town of Rodeo, you can ask the bus driver to let you off at the turn off for Xochicalco, from there you can flag a taxi, they pass frequently on the main road where the bus lets you off, taxi costs about $25 pesos). It costs 40$MXN. An option for the return to Cuernavaca is to take a taxi to Rodeo, and wait outside Restaurante La Pasadita on the Cuernavaca bound highway to flag down a passing bus. Lasser bus lines also runs a bus (blue and white with "lasser" written huge on the side) from their station, listed on Google Maps as Transportes Mibus Terminal SA de CV, on the north side of Adolfo Lopez Mateos, just east of De Los Arcos. It is a lower class bus that doesn't take the toll road, but rather stops frequently along the way, taking about an hour and a half; however, it stops and picks up right at the entrance to the archeological site (not the museum). Last bus returning to Cuernavaca leave Xochicalco at 18:30. 10$MXN (Jan. 2016).
Visiting both Cuernavaca and Xochicalco in a day trip from Mexico City will be busy but do-able.
64$MXN provides access to the archaeological zone and the museum.
There are a couple of small shops on the road down from the archaeological zone and on the road between the ruins and the museum.