culture is important due to the influence it had in the area. It is possible it spread to southern United States, 500 BCE. There are theories that the first Guanajuato inhabitants belonged to this culture. Ceramics of this culture is earlier than the classical mesoamerican period, includes angular figurines with geometric shapes. The Acámbaro museum exhibit pieces from the Purépecha, Mazahua, and Otomi cultures. Apparently the Chupícuaro culture developed in a vast territory, or it was defined as Chupícuaro style or tradition (Beatriz Braniff) in, Guanajuato, Michoacán, Guerrero, Mexico State, Hidalgo, Colima, Nayarit, Querétaro and Zacatecas. It is estimated that Chupícuaro facilitated the northward expansion of Mesoamerican elements (cultural roots of western Mexico and perhaps Northwest, comparable with the Olmec culture throughout Mesoamerica. Chupícuaro had an important cultural development and expansion of its style in distant areas from the diffusing center and influenced ceramic traditions, which lasted until the end of the classical period, and even into the Postclassical, as seen in Purépecha Michoacán ceramic. At the end of 1985, at the first prehispanic societies meeting, in relation to the Chupícuaro culture it was noted, that Chupícuaro tradition ceramics manufacturing groups, should be considered part of Mesoamerican stratified societies, with a definite political and territorial structure and not as isolated village societies, lacking ceremonial centers and architecture. From that first impulse, subsequent social groups presented own cultural expressions, at regional level in the Mesoamerican context. The Site The construction of this ceremonial center is estimated towards year 1200 CE, and it functioned until 1536, when Spaniard destruction of the Purépecha civilization occurred. This is confirmed by the finding of a prehispanic characteristics burial, in which several European glass pieces were found, which means that when these materials were present in the Mexico plateau, in western Mesoamerica prevailed prehispanic cultural patterns. Discovery and investigations The first excavations season commenced in December 1977. The site was vandalized by plunderers since the beginning of the last century, had excavated the site removing artifacts and by farmers that cultivated on the structures. Up to that time no archaeological work had been made in this region that revealed any antecedents for the need to initiate works. The site topography was the only clue as to location of the structures, since initially there were visible signs of them; mounds could be seen mainly at the top of the hill. Once the first wall was found, it