Templo y exconvento de San Guillermo

Augustinian friars founded the Totolapan convent in 1534, with Fray Jorge de Ávila in charge of the building, the same friar who later worked at Atlatlahucan. The church honours Saint William of Maleval, whose Williamite hermits were among the groups later folded into the Augustinian order. In 1537 it took in the friars who had walked out of Ocuituco after a quarrel with Bishop Juan de Zumárraga, and since 1994 it has been one of fourteen monasteries below Popocatépetl on UNESCO's World Heritage list.

The complex has a single-nave, barrel-vaulted church, a cloister, an atrium and posa chapels. What sets it apart is that neither the atrium nor the friars' orchard was ever built over, so both survive as open ground, which almost never happened at colonial convents. Medallions carved with the monograms IHS and XPS, Greek shorthand for Jesus and Christ, cover the façade, and inside are murals of Augustinian friars and red geometric patterns that mix Renaissance, medieval and Moorish ideas.

The convent's fame rests on the Cristo Aparecido. The story goes that around 1543 an Indigenous man handed a crucifix to Fray Antonio de Roa and then vanished, and the town took it as a miracle. In 1583 the image was taken to Mexico City, where it stayed at the convent of San Agustín until 1861, when the Reform Laws emptied the friaries and it came home in a procession on foot. Its fair falls on the fifth Friday of Lent and draws pilgrims from Morelos, the State of Mexico and Iztapalapa, whose San Miguel neighbourhood has walked here every year since 1908.

The earthquake of 19 September 2017 hit San Guillermo harder than any other historic building in Morelos: the main roof caved in and the bell towers fell. INAH's Morelos office reported the cloister restored by 2022, with help from the government of Chile, and in 2023 put out to tender the rebuilding of the nave vault and bell tower. Ask in town which parts are open before you plan the visit.