The Benedictine monastery of Samos, one of the oldest in Spain, benefited from the protection of kings and popes. Built over different periods, the abbey became a cultural symbol of Galicia. It shows a blend of the Romanesque, Gothic, Renaissance and Baroque styles. It was founded in the 6 C by San Martín Dumiense, who dedicated it to the martyrs of Antioch, San Julián and Santa Basilisa. Most of the present construction was built between the 16 and 18 C.
The abbey is remarkable for its robust and austere appearance. The slate masonry matches the majesty and beauty of the scenery. The cloisters are worthy of note. The church, built in the Neoclassical style in the middle of the 18 C, consists of three naves -the central being the highest and widest-, which forms with the transept crossing, the figure of a Latin cross. At the junction of the two arms rises a cupola with ovolos, over a drum, the whole structure being supported by four semicircular arches.
The main façade, in Baroque style, is made of ashlar masonry. It consists of two doorways, one opens onto the monastery, and the other onto the church. The most important of the two is divided into two bodies and is flanked by four Doric columns supported by pedestals.
The different sections of the monastery are organised around two cloisters. The Gothic Nereidas cloister, the older, has a Romanesque portal and is covered by barrel vaulting. Its construction took 20 years (1562-1582). The Feijoo or big cloister was built in the late 17 C. Its style shows the transition from the Renaissance to the Baroque periods. The sacristy of the monastery, built between the end of the 18 and beginning of the 19 C, has an octagonal floor plan. It is surmounted by a cupola set on squinches and semicircular archs.