Tehuacán is the second largest city in the Mexican state of Puebla, nestled in the southeast of the valley of Tehuacán, bordering the states of Oaxaca and Veracruz. The 2010 census reported a population of 248,716 in the city and 274,906 in the surrounding Tehuacán municipality, of which it serves as municipal seat. The municipality has an area of 390.36 km².