Marquardt II von Grumbach, Vogt of Neustadt Abbey built a 'hunting lodge' on the hill where the Rothenfels castle stands today. Around 1200 the castle was rebuilt and the bergfried made form large bunter blocks on a square plan added. Construction of the new castle wall also started with large blocks but was finished with quarrystone.
In the 16th and early 17th century Rothenfels faced hardships, e.g. during the German Peasants War (1525) when the insurgents occupied and burned the castle. The Thirty Years' War brought another period of destruction: the castle was repeatedly occupied by passing armies and sacked.
Today Rothenfels Castle is associated with the Catholic youth movement 'Quickborn', and serves as a Christian education and conference centre. The castle is also a German Youth Hostel Association (DJH) youth hostel.
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.