Tlalnepantla, city, northeastern México estado (state), central Mexico. At an elevation of 7,474 feet (2,278 metres) above sea level on the Río Tlalnepantla, it was founded by the Otomi Indians and conquered by the Aztecs; archaeological remains have been found on the site, and two Aztec pyramids are nearby. The city’s church was begun in 1583. Originally an agricultural and livestock-raising centre, Tlalnepantla has become a northwestern industrial suburb of Mexico City. It is an important transportation hub, receiving and servicing various railroad lines. Among the city’s varied industries are iron and bronze foundries, basic chemical plants, and factories manufacturing mosaics, instruments, machinery, and electrical equipment. Pop. (2010) 653,410; (2020) 658,907.