Matlatzinco.

the name for the Toluca valley; but another place with this name was just to the south of Quauhtinchan, along the Atoyac River, near the contemporary pueblo of San Juan Tzicatlacoyan in the state of Puebla; there is still a large archaeological zone there and a mountain named Matlatzin

(Quauhtinchan, sixteenth century)
Historia Tolteca-Chichimeca, eds. Paul Kirchhoff, Lina Odena Güemes, y Luis Reyes García (México: CISINAH, INAH-SEP, 1976), 220–221, note 2.