Calpulalpan sits in western Tlaxcala, close to the border with the State of Mexico and the old routes between the central highlands and the Gulf. It is a modest city, but it has a sharper historical identity than its size suggests: pre-Hispanic trade routes, Franciscan-era religious buildings, and the nearby archaeological site of Tecoaque.
The centre is quiet and provincial, with the Parish of San Antonio de Padua and former convent as its main landmark. The stronger reason to come is Tecoaque, a site that connects the late pre-Hispanic world with the violent first years of the Spanish conquest in a way few places do.
Calpulalpan makes sense as a focused detour if you are moving between Mexico City, Teotihuacan, and Tlaxcala. It is not a broad sightseeing base, but the archaeology is distinctive enough to justify a stop.