If you've seen any of the major colonial cities, even if you've only been to the center of Mexico City, you can tick off this one too. It's actually such a pity that the Mexicans have included these large city centers into this Camino Real site, as it takes away the focus of what this is about. It would have been better to single out certain monuments along the way.
While visiting San Miguel de Allende, I made an effort to go and see the "Former Royal hospital of San Juan de Dios". This building is added to the area that is already inscribed with the San Miguel de Allende & Atotonilco WHS. San Juan de Dios lies in a quiet and original quarter a bit outside of the city center. I was happy to find an inscription monument for the Camino Real WHS here at the little square where the church and former hospital are located.
Construction of the Royal hospital of San Juan de Dios started in 1753. The "hospital" also consists of a church (of course!) and a cemetery. It was located in a strategic location at an obliged point of the pass to the Tierra Adentro. It sustained all ill travelers, no matter what race they were, where they came from, or how poor they were. The church nowadays is still a parish church, but the former hospital seems to have been taken over by an elementary school (although the nomination file says it has become a civic hospital).