The Old Town of Visoki was a medieval royal castle town built during the 14th century on the top of the hill overlooking town of Visoko, Bosnia and Herzegovina. The first mention of the town was on 1 September 1355, in the charter 'in castro nosto Visoka vocatum' written by Tvrtko I of Bosnia while he was a young ban. The town was abandoned before 1503, because it is not mentioned in the Turkish-Hungarian treaty from the mentioned year. In 1626, Đorđić mentioned Visoki among abandoned towns.
The Old Town of Visoki is at the top of Visočica hill, 213 metres high. Its position provides an excellent view at the plains below. The entry to the castle is on the southwest side, with two lookout towers. Passing through the entry you enter to a part that is called Podvisoki, i.e. to the town that was quite small, measuring 60 by 25 metres, and has signs and remains of early medieval houses. The thickness of the castle town walls is about 2 metres. Its position provides an excellent view at the plains below bordered by mountains Romanija, Jahorina, Treskavica and Bjelašnica in the east and southeast, Bitovnja in the south, the mountain Zec and Vranica in the Southeast, Vlašić in the west, and Tajan and Zvijezda in the north. The entry to the castle is on the southwest side, with two lookout towers.
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.