Source: Photograph by WTL© (2009) on site in the Paso de Cortés, Puebla, México.
Image: The monument marks the place where Cortés and his party spent the night on their trek through the Trans-Mexican Volcanic Belt on their way to Amecameca and eventually to enter Tenochtitlán from the south side of Lake Texcoco.
Comments: The elevation at this marker is 11,150 ft. Paso de Cortés = The Cortés Pass. On the linked photo you can see the condition of the marker itself. See: => Paso de Cortés #5a.