San Cosme and San Damián Collegiate Church was built based on an earlier Romanesque church. It is a 15th century Gothic church. It has a Latin cross floor plan, three naves and a crossing. The town's most illustrious families are buried in the vaults. The Count Fernán González and his wife Doña Sancha are buried in the presbytery, in a 4th century Spanish-Roman tomb. In the cloister, built in the early 16th century, we can find the Gothic tomb of the Infanta Cristina of Norway, first wife of the Infante Philip, brother of Alfonso X the Wise. In the church, the main altarpiece is Baroque and the organ dates from the 17th century. It has a wide range of religious art pieces: Romanesque capitals, panels by Berruguete and Van Eyck, gold items by the artist Calahorra, liturgical robes from the 16th to 18th centuries, and the extraordinary "Adoration of the Magi" triptych, an anonymous carving with Flemish influence.