The ancient urban center of Teotihuacan covered about 20 square kilometers.
Teotihuacan was an immense city that flourished in the highlands of central Mexico, near modern Mexico City, from about 100 BC to AD 650, long before the Aztecs of the 1400s. It covered about 8 square miles and housed around 80,000 people. Teotihuacan was one of the largest ancient cities anywhere in the world. Its influences were strongly felt throughout central and southern Mexico, and impacted even the distant Maya of Yucatán and Guatemala.
Teotihuacan is a UNESCO World Heritage site, visited every year by millions of tourists, who are awed by its vast ceremonial center, its art and its immense pyramids, among the largest anywhere in the ancient New World and comparable to the largest in ancient Egypt. But most of the city is still unexcavated and not seen by tourists.
Multiple archaeological projects are ongoing, carried out by Mexican and other institutions. Arizona State University faculty and students play a leading role in these projects, and ASU maintains a large research facility adjacent to the site.
Unlike many ancient cities, much of the archaeological site is not deeply buried under modern settlement. Because of this, archaeologists can excavate and reconstruct large parts of the city and create an unprecedented story of ancient urban life.
Teotihuacan has much to teach us about the origins and declines of cities, alternative forms of government, the nature of ancient urban life and the ways that religion, governance, markets and economies can change through time. These and many other questions about the ancient city can be answered only if archaeologists continue their fieldwork at the site.
As archaeological methods continue to improve, excavations are becoming more informative and Teotihuacan is beginning to give up its secrets to science. These advances are the fruit of international and inter-institutional collaborations, in which the ASU-managed archaeological facility at Teotihuacan plays a vital role.
For more information, see the following blog posts about Teotihuacan: