Sokolac Castle back to medieval times, while the town was held by the noble Frankopan and Gorjanski families. The castle was part of an important medieval fortified city held by Frankopan family. The cast was documented first time in 1411.
Sokolac Castle was an extremely grand building, dominated by the powerful perpendiculars of the entry tower, and the Chapel of the Holy Trinity. The entry into the burg was through a square, three-storey tower, the façades of which were relieved with lesenes linked at the top with blind arcades, making it a unique specimen in the whole of Central Europe.
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.