Teotenango was in important pre-Hispanic fortified city located in the southern part of the Valley of Toluca. It was initially founded during the last stages of the Teotihuacan civilization by a group generally referred to as the “Teotenancas.” Later, the Matlatzincas conquered the city and expanded it. The city existed for about 1,000 years, being abandoned only after the Spanish Conquest of the Aztec Empire.The name Teotenango is derived from three Nahuatl words: “teotl” (god, sacred, divine, authentic or original), “tenamitl” (wall, fence or fortification) and “co” (place or in) which lends itself to different translations such as “in the place of the divine wall,” or “in the place of the original fortification” or “in the place of the all of the gods.” However, “teotl” began to be used to distinguish this pre-Hispanic site from the town that was constructed in the valley below by the Spanish after the Conquest. This is confirmed by the Teutenanco Chronicles, written in 1582, but the Original Chronicles of Chalco-Amaquemecan state that the site was also known as “Cozcuauhtenanco” (walled place of the buzzards) due to the Teotenaca-Matlatzinca military order that protected the city.At its height, the city was densely population with a main road about 1,400 meters long, pyramidal platforms, palaces, a ballgame court, formidable defenses, drainage and water delivery systems. All around the site there are naturally protruding rocks containing petroglyphs with various signs and symbols. However, only a fraction of the site, mostly the northeast section which contained the ceremonial center, has been excavated and preserved.The site is located on top of a large hill known as Tetépetl, which is located just west of the modern town of Tenango de Arista at a height of 2,700 meters above sea level. It is 25 km south of the Mexico State capital of Toluca, in a sub-valley of the Valley of Toluca named the “Valley of the Matlatzinco” by the Spanish, due to the dominance of this ethnic group here.