Cuicuilco is an important archaeological site located on the southern shore of Lake Texcoco in the southeastern Valley of Mexico, in what is today the borough of Tlalpan in Mexico City. The settlement goes back to 1400 BC.Cuicuilco flourished during the Mesoamerican Middle and Late Formative periods.
Today, it is a significant archaeological site that was occupied during the Early Formative until its destruction in the Late Formative. Based on its date of occupation, Cuicuilco may be the oldest city in the Valley of Mexico and was roughly contemporary with, and possibly interacting with, the Olmec of the Gulf Coast of lowland Veracruz and Tabasco.
Wikipedia https://en.wikipedia.org/wiki/Cuicuilco
Address Tlalpan 14060, Mexico
Coordinates 19°18'2.653" N -99°10'54.27" E