The Romanesque building was begun in 1129 and various Gothic and Baroque additions have been made. At the chevet, the Chapel de Nuestra Señora de los Ojos Grandes (Our Lady with large eyes), a work by Fernando de Casas y Novoa, is a fine example of such additions. The north portal, housed under a porch built in the 15C, has a fine Romanesque Christ in Majesty.