Greifenstein castle overlooks the Danube river. Approximately opposite is Burg Kreuzenstein, on the north shore of the Danube. The castle is thought to be built around the 11th century, and was first mentioned in 1135. However, the owners of the castle changed owners frequently during its service from the 11th century to 1918. It began life playing a significant role in the defense system along the Danube.
More recently, in the 16th century, the castle served primarily as a notorious prison of the ecclesiastical court. Throughout history, the castle was repeatedly invaded and damaged, but repaired, again and again. It was inhabited until about 1770, when it was abandoned and fell into disrepair. Until 1803, it belonged to the Bishops of Passau.
Johann I von Liechtenstein refurbished it in 1807–08 in the Romantic style but at the end of the 19th century, the castle fell again and was sold in 1918, coming into private ownership.
Today The castle has remained in private ownership and is presumed to be on sale.
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.