This generous portería doubled as an open chapel in the early years of the monastery—the niche in the rear wall with the sculpted cross probably marks the location of the original altar. Behind the first, broader arch beside the church, a carved doorway gives access to the convento.
The simple forms of the portería arcade are repeated in the small tree-shaded cloister, whose surrounding corridors and conventual rooms were once lined with 16th century murals. Although all of the narrative murals formerly adorning the lower cloister have been effaced, the striking upper frieze is still there—a complex arabesque border of fruit and foliage, replete with demonic heads and trumpet-blowing angels.The strange device of a heron pursuing a fish against a watery blue backdrop appears at intervals along the frieze. Immediately below the frieze, a superimposed looped and knotted Franciscan cord runs around the cloister.
The murals in the former Sala de Profundis, adjacent to the cloister, are the most complete in the convento. At the far end of the room, now used as a sacristy and parochial office, the entire wall is covered by a handsome narrative triptych framed by a painted arcade with delicate arabesque friezes.
Draftsmanship is self-assured throughout, with bold lines shaded in a blue-black grisaille and selectively accented with red ocher washes. The elongated figures are based on Northern European Mannerist engravings with elegant folding draperies, expressive hands and somber faces, and are superimposed on stylized landscapes with trees, churches and turreted medieval castles, each including varying views of the jagged sacred mountain of Cerro Xihuingo, a prominent local landmark. Native flora and fauna also appear, including agave and rabbits—more subtle references to the pulque cult of ancient Tepeapulco.
The tender Nativity of Jesus occupies the center panel. Note the Star of Bethlehem in the sky in the Aztec style of a comet.
The Nativity is flanked on the left by a fine Adoration of the Magi, in which the robust Three Kings overshadow a meek Virgin and Child.
On the right, a touchingly domestic Holy Family is shown against a background of rocky crags and draped crosses that prefigure the Crucifixion. Note too the eagle talon base of the fruit bowl on the table.
The Upper Cloister
This area contains the largest and most diverse group of murals.
The Crucifixion, with its red painted cross stands at the top of the stairs. Although the face of Christ has been effaced the figures of Mary and St John stand solemnly on either side. Again the tumbled crags of the Cerro Xihuingo rise in the background along with trees and steeples. A rabbit nibbles on a cactus at the foot of the cross.
The partially damaged seated Virgin and Child with two friars follows the same format, the figures set against a wooded landscape.
Three other panels depict well known saints and martyrs—tall, elegantly clad figures again set in backgrounds filled with anecdotal detail: a magisterial St Paul; St Lawrence accompanied by his grill in a vivid landscape of birds, trees, churches and mountain; and finally St. Sebastian, in his usual pose tied to a tree, suffers stoicly, pierced by the arrows of a muscular duo of helmeted Spanish archers.
But perhaps the most interesting mural of this group is a well-preserved Mass of St. Gregory in the northeast corner. This little illustrated mural subject concerns an apocryphal story in which the saint, while celebrating mass, experienced a vision of the Risen Christ, surrounded with the Instruments of the Passion.
Accompanied by two deacons, St. Gregory is seen elevating the host before a panoply of the Arms of Christ. Unfortunately, Christ's face has been obliterated by the overpainted looped cord.
Here, as elsewhere in the monastery, the painted friezes are always imaginative. The upper border, like that above the sacristy frescoes, artfully weaves cartouches of the Five Wounds and the young Christ into an lively arabesque of cherubs, birds, fish, leaves and fruits. Rattlesnakes entwine with doves in a frieze decorating one of the friars' cells.