The Earliest Monasteries on the Slopes of Popocatepetl (Spanish: Primeros Monasterios en las faldas del Popocatépetl) are sixteen earliest 16th-century monasteries which were built by the Augustinians, the Franciscans and the Dominicans in order to evangelize the areas south and east of the Popocatépetl volcano in central Mexico.

These monasteries almost uniformly feature a very large atrium in front of a single nave church with a capilla abierta or open chapel.

The atrium functioned as the meeting point between the indigenous peoples and the missionary friars, with mass for the newly converted held outdoors instead of within the church.

The monasteries in Morelos are located in the municipalities of Atlatlahucan, Cuernavaca, Tetela del Volcán, Yautepec, Ocuituco, Tepoztlán, Tlayacapan, Totolapan, Yecapixtla and Zacualpan de Amilpas.

The monasteries in Morelos are located in the municipalities of Atlatlahucan, Cuernavaca, Tetela del Volcán (including the one in Hueyapan), Yautepec, Ocuituco, Tepoztlán, Tlayacapan, Totolapan, Yecapixtla and Zacualpan de Amilpas.

[3] They were declared a World Heritage Site on 17 December 1994, due to being the model for monasteries and evangelism on the American Continent.

[4] They represent the adoption of an architectural style by the first Franciscan, Dominican and Augustinian missionaries, which included the use of open outdoor space.

[2] There is disagreement as to whether the monasteries represent a complete imposition of European design or whether they adopted certain aspects of indigenous ceremonial spaces.

[5] However, there are claims that the money allocated for the restoration work is insufficient for the job and far less than has been budgeted for other landmarks such as the Basilica of Guadalupe or even the Palace of the Marqués del Apartado.

The route then moves east and somewhat north through Tepoztlán, Oaxtepec, Tlayacapan, Totolapan, Atlatlahuacan, Yecapixtla, Ocuituco, Tetela del Volcán and Hueyapan before ending in Zacualpan de Amilpas.

[4] Since most indigenous peoples could not read or write, the churches and open chapels were painted with Biblical scenes in order to evangelize through the images.

[5][6] Decorative elements in both vary, often mixing different trends that were prevalent in Europe at the time, such as rose windows common on French cathedrals, portals similar to those in Spain and even Islamic style triangular altars.

The Augustinians arrived in 1533 and founded the monasteries in Ocuituco, Totolapan, Yecapixtla, Tlayacapan, Atlatlauhcan and Zacualpan de Amilpas.

[6] The monasteries served as the cornerstones for the towns founded and refounded by the Spanish during the very early colonial period, with the rest of the indigenous population settled or resettled around it.

[3] The Dominicans gave greater priority to economic development of the areas they evangelized, taking advantage of the fertility of the land.

[6] The last round of major renovations and changes, which included the restoration of its murals by specialists and the addition of modern elements, especially in the main altar area, occurred in the late 1970s and early 1980s.

[14] Located on a hill in the Tepozteco Valley, the monastery of La Natividad de Nuestra Señora in Tepotzlán was built between 1550 and 1564 and still towers over the other buildings in the town.

[14] There is evidence of syncretism of indigenous and Catholic beliefs such as the image of an angel with European facial features but with eagle's wings, similar to those which can be found on Quetzalcoatl.

In the interior, there is a fresco with a xoloitzcuintle dog with a torch in its mouth and a border around the walls with squash flowers and roses, surrounded with precious stones, including a native one called “chalchihuite.”[12] The plaza in front of the atrium of the monastery in Tepoztlán is crowded with a tianguis market which sells everything from basic food staples to New Age paraphernalia.

[4] Here are found the best preserved of the complex's mostly black-and-white mural work, pre-Hispanic and colonial pieces and well as some mummified remains from the 18th century.

[11] The preserved murals cover over 2,700m2 and depict figures and scenes such as the Dream of Saint Joseph, Catherine of Siena and the Presentation of Christ at the Temple.

[4] The Dominican monastery of Santo Domingo in Oaxtepec is located on a fairly steep hill over a pre-Hispanic ceremonial platform.

[14] The monastery of Oaxtepec has pillars in the cloister with images of saints, and barrel vaults decorated with repeating motifs such as fleur-de-lis.

[9] The monastery of San Mateo Apostol in Atlatlahuacán was built by the Augustinians around 1570 over the remains of a pre-Hispanic temple in the highest part of the town.

[6] In the cloister, one of the principal attractions is one vault on the ground floor, decorated with a chain made with images of the Sacred Heart of Jesus.

[4] There have been some modifications to the buildings since they were built, but one well-preserved element is its 16th-century stone fountain, the oldest of all the monasteries of the World Heritage Site.

[14] The monastery of San Juan Bautista in Tetela del Volcán was built by the Dominicans in the first half of the 16th century and was even visited by Hernán Cortés.

The façade of the church is considered to be one of the purest examples of Renaissance architecture in New Spain,[6] but it does features a Gothic style rose window.

[6] Calpan was subdued by Cortés personally in 1522 and the Franciscans arrived here to build the San Andrés Apostol monastery complex in 1548 under Juan de Alameda.

[17] The Asunción de Nuestra Señora monastery in Tochimilco receives water from the volcano via a long aqueduct which brings the liquid directly into the building as well as to a 16th-century fountain in the plaza of the town.