Branzoll Castle was built around the year 1250 by the Lords of Sabiona. Between 1465 and 1671, it was the site of the Prince-Bishop's court judge. In 1671, it was destroyed in a fire. In 1895, reconstruction began. While the castle-keep still contains parts of the former fortress, the residential tract is completely new. The view from the church square of the buildings on both sides and the castle looming over it all is among the architecturally most breathtaking sights the city has to offer.
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.