A large Romanesque building dating from the 12th century, located in the heart of the historic centre of the town, built with granite ashlars and several rows of red sandstone. One of the most notable parts of the complex is its apse, which has an open gallery in its upper part, with influences from the Rhineland or the north of Italy. Other points to highlight are the cloister, with fifty sculpted capitals, and the sacristy, which both date from the 16th-17th centuries. Historically, the main function of the building has been that of worship, but over time it has also had other uses, including serving as a fortification.