The Earliest 16th-Century Monasteries on the Slopes of Popocatepetl is a serial property with 15 component parts located in the states of Morelos, Puebla and Tlaxcala in Mexico, built as part of the evangelisation and colonisation of the northern territories of Mexico. They are in an excellent state of conservation and are good examples of the architectural style adopted by the first missionaries – Franciscans, Dominicans and Augustinians – who converted the indigenous populations to Christianity in the early 16th century. They also represent an example of a new architectural concept in which open spaces, including wide atria and posa chapels, are of renewed importance. The influence of this style is felt throughout the Mexican territory and even beyond its borders.