by the artificial leveling and conditioning of large terraces on which the structures were built using stones and clay mortar and covered with overlaid stone slabs. Dr. Roman Piña Chan arranged the site in two separated architectural systems, in an east-west direction on the plateau, to facilitate research. System A is located in the western side and System B, in the eastern side. System A This set includes a two bodied overlaid structure with stairway on the west side. An altar is located at the front, in the center of a square, which is surrounded by residential houses foundations, probably for the ruling class. System B It consists of a temple basement with three overlaid bodies, stairway with sloped wall (alfarda). In front of the structure is a small altar, with several residential structures surrounding it. Some of the monuments were coated with small imbricated stone slabs (overlaid as a roof tiles), a characteristic practice of the Otomi architecture. Archaeological investigations have shown that temples and rooms were roofed with a wooden beam structure, covered with a thick clay sealing layer. All buildings had stucco floors and stone furnaces, probably used for cooking, burning incense or as room heating stoves. Structures The ceremonial center covers 300 m (north-south) and 200 m (east-west). Released buildings are as follows: The Palace The Palace is located almost at the site center. The ceremonial building preserves the architectural style of the place, recessed stairways and stuccoed stone. It was identified as a palace, because at the top were found wooden pilaster elements at the entrance, as well as stone foundations and smokers, these depict religious activity. It has two bodies, covered with a wall of stone slabs and a central stairway case to the west. On the north and eastern sides is a 30 cm wide walkway. Atop the structure are indications of a temple-room, with a hallway in front and three entrance spaces, separated by two wooden pillars, as access to the aforementioned ample space, which had two furnaces or tlecuiles. The presence inside of Sahumerios (Smokers) is an indication of the religious purposes of the place. This building is a pyramid, roofs were made of perishable materials, such as adobe, dirt, tile and palm leaves, so could not be preserved over time. Altar Located west of the Palace. Possibly had a single body, although there is evidence of two stairs towards the