Its origins seem to have been the old Church of San Juan, which grew into a monastery in the year 1124. Oit was founded as a Cistercian monastery by Doña Teresa, Alfonso VII´s daughter, in 1142, bringing French nuns from Claraval. Other writers refer to it as Cistercian in the year 1153, when it adopted the worship of St. Mary. In the year 1528, it joined the Cistercian Congregation, in Spain, with the building´s reconstruction beginning at that time, including the church, with most of the work taking place during the 16th century. The slender church stands on a Latin-cross ground plan, with three aisles in five sections along the main arm; side arms marked on the ground floor, five rectangular chapels, the central the main one. The aisles have Ogival, ribbed vaults, with lunettes and coffering. In the transept, there is a dome over pendentives with cupola. The facade flay and austere. The church was begun in the year 1598, with Juan de Tolosa as master-architect, from the Company of Jesus, and creator of the Hospital of Medina del Campo, in addition to other builders. Construction work ended in the year 1607, inscreibed on the facade.
The monastery has two cloisters, the oldest of which is in evolved Ogival style, square, with five semi-circular arches per side and nine-pointed star-vaults; the upper part has Renaissance and Baroque arches and windows. The second cloister is square, elegant, with four semi-circular arches per side over free-standing Renaissance columns, and sculpted medallions and shields, all dating from the 16th century. It also has a large, monumental stairway down to the church and a fine sacristy.
The regular or processional cloister is connected to the church. In the early 1980s this area was rescued from a state of ruin, and once restored it began to be used as a school.
Opening hours: From 11.00 to 14.00 h. and from 16.00 to 20.00 h. every day.