Of the rectangular buildings with free-standing keep, built in the 12th century, only the remains of the east and south wings of what used to be an important castle are preserved. The alterations carried out in the 18th century, following diverse war damage, resulted in the palatial building as it can be seen today. During the Second World War the castle was seriously damaged, but was reconstructed in 1952. This construction work was carried out in a simple reduced form; only on the valley side does the castle resemble its former image. Schleiden castle today is merely the remains of what used to be a much more extensive castle complex of several buildings.
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.