This section begins with the arrival of the Chichimeca peoples to the Basin of Mexico around the year 1250. It was under the leadership of Xólotl that Tenayuca was founded, and to this group are attributed the earliest ceremonial center constructions. Illustrations show scenes of Chichimeca life: nomadic hunter groups who migrated from the arid north, dressed in animal skins, and lived in caves. A display case presents orange ceramic vessels with black grass-like designs, typical of Tenayuca's early ceremonial phase.

The remainder of the section focuses on the site's period of splendor. It features characteristic orange vessels with black painted designs known as "Azteca III", and red vessels painted in white and black, called "Rojo Texcoco". Among the most notable are pulque cups used in ritual or social contexts.