Construction of the complex started in 1740 by Father Luis Felipe Neri de Alfaro who, according to tradition, was called upon by a vision of Jesus with a crown of thorns on his head and carrying a cross. The main feature, and why you should visit, is the wonderful Mexican Baroque mural work that adorns the main nave and chapels. The paintings have a definite indigenous influence. This was chiefly the work of Antonio Martinez de Pocasangre over a period of thirty years.
The Santuario remains a place of worship and penance to this day, attracting as many as 5,000 visitors every week. Pilgrims come for exercises in flagellation and fasting. During Semana Santa, or Holy Week, it is estimated that 5,000 perform these exercises and wear crowns of thorns on their heads. It is one of 33 weeks out of the year when visitors, mostly from the center and north of the country, visit the Casa de Ejercicios to perform penance. A complete cycle of penance, prayers and meditation lasts eight days.
The paintings are stunning, so I highly recommend making your own pilgrimage to the site. Make sure to wander through the streets surrounding the church where you will see some of the whips for flagellation and crowns of thorns for sale. Very interesting. On my last trip, I was so pleased to be able to tour two chapels, that are normally closed to the public, the Camarin de los Santos Apostles and the Capilla del Calvario, both with amazing statutes and painted ceilings.
Once you visit the chapel, we recommend visiting Galeria Atotonilco for wonderful folk art. Just call owner Mayer Shacter for an appointment and then have lunch on the terrace at Nirvana Restaurant and Retreat. I suggest making a reservation as it is popular for lunch.
Though not my thing, the La Gruta hot springs nearby are also enjoyed by many.
I also recently found the casual El Coyote Flaco Restaurante, near Atotonilco. It is a casual restaurant serving good food and wood fired pizzas. They have a full bar and offer music on Sunday afternoons. I went with local friends and enjoyed being outside on a lovely afternoon, listening to music. They are open Wednesday to Sunday.