Santa María de Sandoval Monastery was built on land donated in 1142 by Alfonso VII to Count Pedro Ponce de Minerva and his wife Estefanía Ramírez.
After receiving numerous donations and possessing extensive territories, it entered decadence in the fifteenth century. In 1592 and 1615 it was grass of the flames, reason for which it had to be rebuilt. The permanence of the monks remained until 1835, date in which the exclaustrado with the confiscation of Mendizábal took place.
Its architectural layout responds to that indicated by the Cistercian Rule. It has two great cloisters, although the one that is conserved is realized in century XVII, in him it maintains the severity of the Chapter Room.
The church is of plant of Latin cross, with three ships, cruiser and semicircular apses. The primitive gateway by the north gable, is Romanesque, and presents a unique resolution of its archivolts. The west, which is now the entrance, is a pointed arch, standing out its beauty by the simplicity of its construction and decorative elements based on floral elements, figures of monks and the calvary of the tympanum of the door. In the south gable rises the belfry that is of later times.
In its interior they emphasize the sarcophagi of the founders, arranged to both sides of the altar, in the middle mounted the major altarpiece in which participated between 1605 and 1618 Pedro Sánchez, Cistercian monk
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.