It corresponds to the zone of initial explorations formed by four structures, two of them restored and rectangular in shape, with columns in front that limit the living spaces; these structures are part of a plaza with pyramidal base, central altar and other unexplored structures (mounds to the north and east).

Circular temple dedicated to Ehécatl-Quetzalcóatl (Structure 1): In this set the circular pyramid stands out, the most important structure of the archaeological zone that, for its form and finishes, constitutes one of the most beautiful works of the pre-Hispanic architecture in the west of Mexico. The monument is round with 24 m in diameter and 4 m in height, originally was a cylinder of vertical walls, as a compact drum, crowned by a parapet perforated by cross-shaped loopholes, which give the building the appearance of a large bracero, with five stairs harmoniously distributed in its contour. In the superior part there are two rectangular adoratories and it is known as monument to Quetzalcóatl or Ehécatl, due to its characteristics and architectural elements.