The imposing church stands in the centre of the town of Salas, right in the old quarter. It dates from the 16th century, although other elements were later added, such as the bell tower, the chapels and the portico. The bell tower, located at the east end, is square with two buttresses at the corners and an adjoining semi-circular body with a cul-de-four dome.
A rectangular body juts out of the left side of the church, which was added in the first half of the 16th century. It comprises the portal, under a protective arch, the doorway, under a pointed arch with a fluted archivolt decorated with rosettes surrounded by voussoirs, all framed by a Gothic alfiz bearing a coat of arms in the centre.
Inside, the nave is divided into two bays covered with stellar vaults which are simpler than the one covering the apse, choir and gallery, located at the east end, which consists of ribbed groin vaulting and a three-centred arch.
All the ribs rise from undecorated corbels, the walls thus remaining plain. The church is illuminated via large, narrow semi-circular splayed bays.
The chancel conserves a magnificent Baroque altarpiece by Asturian sculptor Luis Fernández de la Vega, on either side of which there are niches with the praying figures of Archbishop Fernando Valdés Salas' parents. On the north wall can be found the late 16th-century Renaissance tomb of the illustrious founder of the University of Oviedo, made in marble by Italian sculptor Pompeio Leoni (1576-1582).
