You'll find thousands of petroglyphs and archaeological artifacts in the remote deserts of Nuevo León. Boca de Potrerillos (Potrerillos Mouth) is one such site. It has been studied for many years, but for a long time, its creators were a mystery. 

Although the Spanish wrote extensively about the indigenous people of Mexico, they made no mention of a large civilization in the northeast. As such, these enigmatic petroglyphs were attributed to the Aztecs, the Comanche, and the Chichimec. But by the 18th century, there was no trace of these groups in the area.

A wide variety of carvings are displayed, from astronomical symbols to representations of daily hunter-gatherer life. Arrowheads, amulets, pots, shells, and grinding stones have all been found in the surrounding area. While looking upon the site today one would see a barren waste, Boca de Potrerillos was once a thriving indigenous center, whose legacy still lives on in the enduring art of its people.  

Carbon dating on adobe ovens at the site revealed that the settlement they belong to could date to as far back as 8900 B.C., making the artwork much older than earlier thought. The artists remain unknown, although most archaeologists believe the Coahuilteco of southwest Texas and northeast Mexico were the creators.