In the 13th century a castle where the different Kings of Aragon spent some time was built upon the remains of an older building, probably a hospital. The fortress, symbol of the feudal power of the Monastery, finally became the residence of the abbot from the 14th century. It has an attached raised cistern to supply water to the monks and the Cloisters’ jet. King Philip V’s order to destroy the Catalan castles meant that the building became a palace, so that its façades were altered and they built upon the former Gothic courtyard. Since the monastic secularisation, it has been the parish house.