It is located between the Snake Mouth Building and the Palace. It is another elite housing complex, but with only one floor. It has spacious rooms that had false arches as ceilings and a rhythmic pattern of slender columns as part of the walls. The plinth was decorated with the motif that gives the building its name: the stepped fretwork, a symbol frequently used in Chenes and Puuc architecture, but also widely documented in many Mesoamerican regions. Its meaning is a subject of debate, with ideas such as the stylization of the rattlesnake, the cyclical movement of the stars, the opposition of opposites, the change of seasons, etc., having been proposed. In central Mexico it was called xicalcoliuhqui (xicalli = jicara; coliuhqui = twisted or lying thing).