San Agustín Tlaxiaca

Tlaxiaca comes from Nahuatl and means "among the trees of the ball game"; San Agustín was added in honour of the saint of Hippo. Almost nothing is recorded about why the town was founded at this spot in pre-Hispanic times, but remains across the region show that Nahua groups passed and settled here: the Otomí came first, then the Toltecs left their influence on their way to Tula and Tulancingo, and later the Mexica extended their rule over these plains. In colonial times the municipality's main community was Ixcuinquitlapilco, an alcaldía mayor and república de indios answerable to Actopan. San Agustín Tlaxiaca became municipal seat on 16 October 1872.

The town lies in the Mezquital Valley at about 2,360 metres, among plains and low hills of the Trans-Mexican Volcanic Belt. The climate is semi-dry and semi-warm, with 570 to 770 mm of rain a year, heaviest in September and October. INEGI counted 12,328 residents in 2020, nearly a third of the municipality's 38,891, which spreads over 297 km² and has 59 localities. Only 88 people speak an Indigenous language. The municipality belongs to the Pachuca metropolitan area.

The patron-saint fair for San Agustín has a ritual of its own. The town's four barrios, Mexiquito, Casa Grande, Fresno and Huizache, bring the crosses down from the Cerro de la Providencia (also called Cerro Grande or Cerro de las Cruces) to be decorated and blessed, and when the fair ends they carry them back up. Across the municipality pepper trees dominate, with mesquites, ash trees and huizaches in smaller numbers, and the community has a multi-level chapel.