In around 1300 Sostrup was an outlying farm known as Svorttorp but the first written record dates from 1388. The current castle was built in 1586 by councillor Jacob Seefeld. In 1807 the castle was bought by the Danish State and in 1829 by Jakob von Benzon. After this period some changes and restorations were made until the Danish State went into possession again in 1945. In 1946 it was run as a refugee camp. In 1960 the castle was bought by the Danish Cistercian Order. The castle was totally restored and today it is run as a conference centre.
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.