Schlettau Castle dates probably from the 13th century. In the 14th century the castle was extended to a Gothic-style castle palace by the Schönburg-Crimmitschau family.
From 1413 to 1536 Schlettau belonged to the Cistercians. After the secularization in 1536 it became the property of the Saxon Electors, who used it as a hunting lodge. The still existing stuctures consist of a Renaissance section (about 1620) and two Baroque wings (early 18th century). Today it is restored and hosts a museum.
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.