This former monastery was built during the XVI century between 1534 and 1574 under the Augustinians order in Tlayacapan, Morelos
Its atrium, which has large proportions, is the biggest in the state. The facade of the church is decorated with small images of suns and moons The architectural style found in this complex is actually a mixture of several of them, including, Roman, Medieval, Plateresque, Gothic and Moorish.
One of the main attractions of the monastery is the frescos in the entrance and meditation hall. The cloister area and part of the open chapel are currently used as a site museum which contains pre-Hispanic artifacts, Catholic religious objects, religious paintings from the 17th century and more, but the museum is more commonly known for its mummified remains on display. These were found under the floor of the main nave of the monastery church in 1982, during the restoration work. These remains are mostly of children and one adolescent, identified as upper-class Spanish due to their dress. The belief at that time was to be buried in the church as close to the altar as possible in order to reach heaven sooner. Today they can be viewed in the museum in the room which used to be the dispensary. For this reason and others, photos inside the museum area are strictly prohibited.
A particular feature of this monastery is that there is no bell tower, the bells are displayed in bell-gable.
This church was named World Heritage site by UNESCO in 1994.