The church of St Eulalia in Borau is a 16th century building which is at present in a serious state of disrepair. A Romanesque church probably existed before it but only the tympanum with a monogram of Christ remains, set into the north wall of the chancel.

The experts agree that the church as we see it now, was built by Juan de Landerri, who also built the chapel of the Holy Cathedral in Jaca cathedral. This grand church which dominates the highest part of the village, has a single nave, a choir gallery at the western end and a polygonal three-sided apse. Only one chapel remains on the south side and it forms the base for the tower.

The roof in the main nave is a simple groin vault while at the western end there is a false ceiling. The interior decoration offers several pieces of interest. The main altarpiece (16th century) was carried out by Leonardo de Labarzana and his son Lope. It is dedicated to St Eulalia and shows several woodcarvings and panel paintings of different saints, along with sculptures of the four evangelists in a sitting position above the bench. Likewise, the altarpiece of St Peter, by the same masters, deserves a closer look. The figure of St Michael in one of the lateral niches is clearly influenced by the Lasala altarpiece created by Juan Moreto in Jaca cathedral.

The choir gallery is closed off with a wooden ballustrade of great artistic value. Other Barroque pieces are also conserved including the altarpiece of the Immaculate Conception (1692), the altarpiece of the Virgin of the Rosary (18th century) and a crucifiction from the 17th century.