The Burgkirche ('castle church') is one of the largest and most imposing fortified churches in western Germany. The church is surrounded by a cemetery, which is surrounded by walls. The Romanesque tower of the church with Gothic battlements and turrets is the oldest part of the church, which was built in several phases in the late Gothic period. The restored stained glass windows and paintings in vaults - both from the 15th century - are worth of seeing. The church served as a graveyard of local nobility and has lots of interesting tombs.
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.