The Balaiana Castle is situated on Mount San Leonardo, at 299 metres above sea level, dominating the surrounding valley. You can walk through a staircase carved between granite rocks where the start path is located in the parking area, just 5 km from the village, on the road to Arzachena.
The castle's unique architecture, with features such as the special interlocking blocks of granite corners, dates back to the 12th century. The castle was destroyed by the army of Alfonso of Aragon, who had razed the structure almost completely to the ground in 1442.
The small church dedicated to San Leonardo was built as a chapel of the castle and is a rare example of Romanesque architecture in Gallura. The chapel can be reached via a path just a few dozen metres north of the Castle. The similarity between the churches in Corsica suggests that in the second half of the 12th century there was a shift between the islands of the Mediterranean and the manufacturers who used the granite stone.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.