Located east of the estate, its name means "Place of the Moon" in Nahuatl. It has an extension of 96,042.94 ha, which makes it one of the largest natural areas in the estate. It consists of a huge and deep ravine full of desert vegetation, including some endangered cacti.

The Reserve offers an enormous biological richness and most of the fauna and flora of this region are endemic species of Mexico. The settings are spectacular.

Inside the reserve there are interesting cave paintings that are vestiges of the first settlers of the region.

In the highest part of the ravine is located Metztitlán, a town that was the head of a Metzca manor, which was never conquered by the Aztecs. You can also visit an Augustinian convent from the 16th century, since in the colonial era it was an important center for the missionaries who were in charge of the evangelization of the Huasteca.