The monastery of St. Julian of Samos, founded in the 6th century, belongs to the Benedictine order and is located in the municipality of Samos.

This monastery was an important teaching center for theology and philosophy and is an important stop on the Camino de Santiago, as it has a guest house for pilgrims.

In 2015, when Unesco approved the extension of the Camino de Santiago in Spain under the name "Caminos de Santiago de Compostela: Camino Francés y Caminos del Norte de España", Spain included the Benedictine monastery of Samos in the documentation, under number 617 in the "Inventario Retrospectivo de Elementos Asociados" (Retrospective Inventory of Associated Elements).

The foundation is attributed to St. Martin Dumiense, and it is known to have been renovated by St. Fructuosus in the 7th century. The first written record of the monastery dates from 665, with an inscription mentioning its reconstruction by the bishop of Lugo, Ermefredo. The monastery was abandoned during the Muslim invasion and recovered after the reconquest by King Fruela I of Asturias, when the king's widow and son, Alfonso II of Asturias, sought refuge there, which attracted royal protection.

In the 10th century, the bishop of Lugo, Don Ero, tried to take control of the monastery, but the counts Arias and Gutierre Menéndez repopulated the place with new monks. From then on, the count family maintained good relations with the monastery. In the 12th century, it adopted the Cluniac reform. During the Middle Ages, the monastery reached great importance, coming to own more than two hundred villas and five hundred places. After a fire in 1558, it was completely rebuilt. Although the monks were exclaustrated in 1836 by the disentailment of Mendizábal, they returned in 1880. In 1951, another fire affected the monastery, but it was again restored.

The monastery combines several architectural styles, such as late Gothic, Renaissance and Baroque.

The baroque church was built between 1734 and 1748 with a Latin cross plan and three naves. In its interior the paintings of the four Benedictine Marian doctors and a classicist altarpiece with an image of San Julian stand out. The facade, also baroque, is preceded by a staircase similar to that of the Obradoiro.

The monastery has two cloisters. The Great Cloister, built between 1685 and 1689, is the largest in Spain with 3,000 m². It is known as the "Cloister of Father Feijoo" and is decorated with scenes from the life of Saint Benedict. The Small Cloister, or "Las Nereidas", was built between 1539 and 1582 in Gothic style and houses a Baroque fountain in its center.

The monastery library houses about 25,000 volumes, including incunabula and historical documents of great value.

This small Mozarabic chapel, dedicated to San Salvador, dates from the 9th century and is notable for its trapezoidal floor plan and simple structure.