This Romanesque cathedral underwent significant alterations between the 16C and 18C. Inside, the modification of the Manueline vault in the 16C transformed the building into a hall church supported by twisted liernes. The chancel houses a monumental Baroque altarpiece. The chapter house contains an interesting treasure of sacred art including two reliquary boxes in Limoges enamel, a gospel book (with binding) and a nativity scene by Machado de Castro. The cloister is in the Renaissance style.