Yaonáhuac Municipality is a municipality in Puebla in south-eastern Mexico. History Some people affirm that this municipality was primitively called Hueyaonáhuac and that it was founded by the Otomíes and Totonacas, in pre-Hispanic times. It was under the triple alliance (Mexico-Texcoco-Tlacopan). The Spaniards implanted the slave-driven system of charges. It belonged to the old district of Tlatlauquitepec and in the 1895 it was constituted as a free municipality. Location The municipality is located in the northwest of the state of Puebla. Its geographical co-ordinates are 19° 52' 06" to 19° 59' 48" N and from 97° 21' 54" to 97° 27' 18" W.. It is adjacent to: The north: with Teziutlán and Tochtepec. The east: with Hueyapan. The south: with Atempan. The west: with Tlatlauquitepec. Extension It has a surface of 5,485 km2. Which locates in the place 160 with respect to the other municipalities of the state of Puebla. Orography This municipality belongs to two morphologic regions of level 1.000 towards the north, to the declivity of the Gulf of México and the same level towards the south and to the North mountain range. The North mountain range or mountain range of Puebla is formed by more or less individual, parallel mountain ranges, compressed a con the others and that usually forms great or small high plateaus intermountains that frequently appear stepped towards the coast; whereas the declivity of the gulf is the northern one of the North mountain range towards the coastal plain of the Gulf of Mexico, it characterizes by his numerous volcanic chimneys and isolated hills. The relief of the municipality in general is rough; to the south it presents/displays a more or less flat topography with a smooth declivity the north-south; in agreement pronouncing advances in this direction becomes the reduction more irregular and, by the irruption of an originating mountain range of the west and that crosses the municipality from the central part towards the north in direction southwestern-north. The presence of the mountain range to which the Germancos hill belongs, causes a declivity west-this, that adds to the general declivity south-north. But to the north a series of isolated hills exists that return rough still more the relief, emphasizing the Caxtomaquimatépetl and the Portezuelo. The height of the municipality varies from above sea level. Hydrography The municipality belongs to the northern slope of the state of Puebla, formed by the different partial river