The church of San Serafino, dedicated to the archangel Raphael, is located in the Tirso valley, in the territory of Ghilarza. There is little information on the original late antique construction of the building, of which parts of the single-nave Romanesque hall, dating back to the late 13th century, are still visible. The church has undergone several renovations over time, which have shown, on the inside, the perimeter of the semicircular apse and a large single lancet window with a sloping lintel and ogival profile. On the outside, sections of the original facing made of medium-sized trachyte ashlars remain. Concealed by a portico, the façade has a cross-shaped plugged window and an architraved portal of late Romanesque origin, with rounded leaf capitals and an ogival archway. In the lunette above the portal, bordered by a diamond-pointed decoration, a stone is set with the Agnus Dei between figures of seraphim. On the southern side of the church is a walled-in portal with a lunette described by a semicircular arch, above which is visible a ashlar with the Arboreal coat of arms of the thinned tree. The architrave, described by a lath frame, hosts four figures kneeling in prayer, in which one could recognise the Arborense patrons, in the centre of which is a seraphim and floral elements punctuate the composition.