Santa María de Sar Collegiate Church is a former convent of canons regular who belonged to the order of St. Augustine. It was founded by Diego Xelmírez in 1136 as a concession to the canons who retired under the rule of St. Augustine, thus enabling them to maintain their privileges in the cathedral. In 1548, it was secularised and became a collegiate church. Today, it is a parish that falls under the jurisdiction of the Diócese of Santiago. The church and the northern side of the cloister are preserved from medieval times. It is an important example of Compostelan Romanesque architecture, with a three-nave basilica plan, the central nave being wider than the side naves.

The Colexiata do Sar Museum (MuSar) is to be found in a building adjoining the southern side of the church. The exhibition is spread out across several different rooms. A visit to the museum begins in the reception area where a stone pillar with coupled columns from the workshop of Mateo can be seen. The second room contains, among others, pieces relating to the Sar Priory and monastic life, such as architectural elements from the old 18th century cloister, or baroque sculptures like the St. Roch of Montpellier, with Jacobean iconography.

In the documentary collection, the Foundation Charter of Sar Collegiate Church, signed by Archbishop Xelmírez, is outstanding. The third room boasts pieces relating to the parish life of the church and encompasses the period from the 17th to the 19th centuries, with pieces of gold and silver work, liturgical ornaments and sculptures. The fourth and fifth rooms contain traditional Galician costumes belonging to the Collegiate Church’s folk group, linked to the parish. The tour ends with a visit to the 18th century cloister in which nine arches from the old 13th century cloister remain, and to the Church, to which access from the museum is available for the cultural visit.