Chichimecas in Tenayuca and of the Acolhuas in Huexotla, Texcotizingo and Los Melones. Other important groups were the Mazahuas in the Atlacomulco area. Their center was at Mazahuacán, next to Jocotitlán mountain. The Otomis were centered in Jilotepec. Historiographical texts on Mesoamerican prehispanic peoples have paid little attention to the Otomí history. Many centuries ago, in the territory occupied the Otomi flourished large cities like Cuicuilco, Teotihuacán and Tula. Even in the Aztec Triple Alliance which dominated the Aztec Empire, Tlacopan inherited the Azcapotzalco domains with a majority of Otomi people. However, the Otomi culture is hardly ever mentioned as protagonists of Mesoamerican prehispanic history, perhaps because the ethnic complexity of the Mexico plateau at that time does not permit distinguishing the contributions of the Otomi ancient from those produced by their neighbors. Only until recent years there seems to develop an interest on the role they played by the Otomi in the development of the Mexican plateau cultures, from the Mesoamerican preclassical period thru 1521 CE. Huamango flourished and had its apogee between 900 and 1300 CE. Based on research investigations, it is established that the site occupants formed a hegemonic religious group. It has not yet been established the Huamango constructors cultural affiliation, although ethnic-historical sources information allow the assumption that these are groups of Otomi origins, ancestors of the current Otomi living in the place. Etymology Huamango, means "place where Wood is carved" in the Nahuatl language. This ancient settlement stands majestically in a geological formation known as the San Miguel Huamango Camaye Plateau, formed by Andesite extrusive igneous rocks. About the name Acambay, it is based on ancient documents that mention that this region was called, in Otomi language, Cambay o Cabaye, which may be translated as "God’s Rock" (okha= "God", mbaye= "Rock"). A different theory claims the name is from the Purépecha language, from the word Akamba that means maguey or agave and the "rhi" desinence that means; Akambari or "Place of Magueyes". Investigations Huamango was discovered by architect Edgar Serrano Pérez. The site was excavated by Román Piña Chán and William Folan in the 1970s. It consists of a small ceremonial zone with some temples, located on a ridge overlooking the Valle de los Espejos. Although the dating of Huamango is not as certain as one would like, various lines of evidence point to an Early Postclassic (Toltec period) date for the site (A.D.