The study of the neighborhoods of Teotihuacán is fundamental to reconstructing the history of this great pre-Hispanic city. It makes it possible to identify the different social strata and the social, political, economic and ideological organization of their inhabitants, as well as the forms of integration with the inhabitants of other neighborhoods and other cultures.

The notion that different neighborhoods existed in Teotihuacán emerged from the first studies that considered the site as a great metropolis. However, it was in the decade of the 1960s when a map of the city was drawn up, which allowed us not only to understand its limits, but to detect some of its neighborhoods, like the Oaxacan district and that of the Merchants from the Gulf of Mexico. Later the so-called neighborhood of the West of Mexico was discovered (Millon, 1973).

Since then it has been established that the city covered an area of 7.7 square miles, an extension that goes far beyond the current boundaries of the archeological zone. During its peak, it reached about 200,000 inhabitants, who occupied approximately 2,000 housing units. In addition to the colossal pyramids and religious, political and administrative buildings, the space was occupied by the neighborhoods surrounding the great ceremonial center, arranged and distributed according to a system of two major thoroughfares set perpendicular to each other: the Calzada de los Muertos and the East-West Avenue.

Subsequent studies have increased our knowledge of the different neighborhoods where the majority of the population lived and performed their tasks. One of them, currently under study, is La Ventilla, named after the ranch it is located on (Cabrera, 1996). To date it is the most extensively explored. Thanks to the vast amount of information obtained, it has been possible to deepen our understanding of both its constructive and urban characteristics and the way of life of its inhabitants. This, in turn, has made possible a clearer perception of the urban system of the great city, which is particularly relevant to understanding the social structure.

Through intensive excavations in this neighborhood, numerous buildings of different ranks and functions have been uncovered: administrative, religious and residential, together with dwellings linked to craft workshops. These were grouped in delimited apartment groups with thick walls and bounded by streets that formed a kind of city block.

Some walls of the residential areas exhibit important traces of mural paintings with diverse themes. Also, numerous glyphs or symbolic figures related to writing were painted on the floor of one of its squares.

The hydraulic structures found in this neighborhood include remains of irrigation canals, drainage, artesian wells, water tanks and storage jars embedded in the floors. To this other relevant data may be added, such as the shared courtyards and the presence of thick, high walls, which indicate a kind of defensive system.

Other findings worth highlighting include the handicraft workshops for the manufacture of luxury objects (Gómez, 2000), as well as a space or esplanade without buildings where the tianguis or neighborhood market may have been set up.

Numerous human burials found under the floors of the houses offer an account of the funerary and ritual system of the city's inhabitants. In addition, remains of animals and plants were found, study of which indicates the type of diet and the predominant diseases.

With the knowledge that we have today of this Teotihuacan neighborhood and of others that have been partially explored, we can better understand the level of development the city reached and the changes it experienced over time, from its beginnings—when it was first occupied by sedentary peoples—through its peak of development, to its decline and collapse.

However, there is still a lot of work to be done. So far, most attention has been paid to the more spectacular buildings, but it is important to learn more about the ordinary neighborhoods and the lives of their inhabitants.