The church of St Sabina (or St Sirbana) is located on the SS 129 main road near the turn-off for Dualchi. It can be considered a rarity, or perhaps a legacy, for lovers of unusual buildings. This is due, in the first place, to its setting in an area rich in history and architecture and secondly, because of the characteristics of the building itself. It was constructed in the Byzantine-Judiciary period (C10th - 11th) inside a complex of monuments made up of: a nuraghe of the same name, a sacred well in the "tholos" style and a giants' tomb. There are no other architectural comparisons in Italy - the church is quite simply unique.
According to Emma Blake ("Sardinia's Nuraghi: Four Millennia of Becoming" World Archaeology- 1998) "The church of St Sabina of Silanus seems to have been built according to a design inspired by the single-tower nuraghi from the Bronze Age, which had come to an end not long before".
Not only this, however: it is said that it was built above a sacred nuragic well.

Whether this is true or not, what is certain is that the inspiration for the original planimetry is either a nuraghe or sacred well and the overall result takes the form of a paleo-Christian baptistry.The composite nature of the church is also shown in its variety of architectural styles: from the Romanesque barrel vaults and the splayed window of the central apse, to the tympanum pediment and the central ogival dome.

The church was built in two colours with trachytic and basalt rocks coming from the nearby nuragic village and from the tomb of the giants, and is made up of a cylindrical central body of little more than six metres in diametre. Just before this, there is a small, simply architraved entrance portico and two annexes arranged rectangularly with apses leading to the central body. Inside it preserves a floor slab which was the pillar of the Giants' tomb, some Roman funeral urns and the remains of a sarcophagus.