site The site covers about 12 square kilometers. For study purposes it was divided into three large units. The southern part is the best preserved part. The Acropolis (area where the main structures are located, believed to be the shelter of political, economic and religious powers), is a good example of the settlement. The site is made up by many patios of approximately 50 x 40 meters, or even larger; in some of them obsidian and stone workshops (stone tools) were found, hence a clear division and specialization of its inhabitants work is deduced. According to García Cook, rural people settled in low lands, leaving people with social rank the intermediate areas and, finally, at the top were temples, ball games, and the houses of chiefs and leaders. Evidence indicate that the patios were residential places for Cantona family groups; such is the amount, that in sector V, 620 patios were detected and 997 mounds, including housing units, altars and pyramids. Its architecture is absent of stucco as decoration element, although mud was possibly used to join volcanic rock in addition to the technique of placing stone on stone, as was done to shape walls, alleys, platforms and other archaeological structures. There are two large prehispanic roads; these avenues are framed by high and thick volcanic stone walls, (some of them more than a kilometer long) that together with the streets and roads allowed access to the patios and ceremonial areas, constituting an important access control to the city and internal urban areas; this great fortress also had a moat that protected the city on its limits with the Valley, from possible invasions from this sector. In the highest areas are located ceremonial nature structures as ballgame courts (over 24) 12 of them have a special distribution which has been termed Cantona type, because it has integrated architectural complexes in which generally are a pyramid, one or two plazas, an altar, and several peripheral structures; there is uneven symmetry on its walls, there are discrepancies in orientation or measures. Recent studies indicate that Cantona was besieged by foreign groups, which together with strong climate change, ended up affecting the city, leading to its abandonment. The construction system and size included in its three units, has been considered the most urbanized city known so far in the central Mexican Plateau. Its size is surprising, its roads and stone walls, by its