Wikipedia - Teotihuacán - Encyclopedic entry for what was once the largest city in the Americas. - http://en.wikipedia.org/wiki/Teotihuacan
Teotihuacan - Photograph gallery and description of the "City of the Gods" from the Mesoamerican Photo Archives at Tulane University. - http://eric.tcs.tulane.edu/~dhixson/teo/teo.html
Archeology of Teotihuacan, Mexico - Saburo Sugiyama, Arizona State University, Dept. of Anthropology gives a description of this ancient city, with illustrated reports on excavations, chronologies and maps. - http://archaeology.la.asu.edu/teo/