Hald Castle was built in 1528 by the bishop Jørgen Friis, who was the last Roman Catholic bishop of Viborg. It is said that Friis was one of the first prisons in Hald tower after the Reformation. The castle was left to decay and in the 1700s it was abandoned. Anyway in late 1800s the owned Christopher Krabbe reconstructed the tower which is today the most visible part of the former castle. Today castle ruins are open to the public for free.
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.