The first documented record of Hohenurach Castle dates from 1235, but it was probably built in the 11th century by the Counts of Urach. Count Ludwig I of Württemberg updated the castle in 1427, building a new castle on the existing foundations. Following heavy damage in 1547 during the Schmalkaldic War, Duke Christoph of Württemberg had the castle rebuilt in 1551. From the 16th century onwards, the castle complex also served as a state jail, whose inmates included the Tübingen Professor Nicodemus Frischlin (1547-1590).
As a military facility Hohenurach Fortress also posed a constant threat to the citizens of the nearby town. It wasn't until 1765, however, that Duke Carl Eugen of Württemberg decided to move his soldiers to the town and had Hohenurach Fortress torn down. All that remains of the castle site is a towering ruin – one of the biggest, mightiest and most important ruins in southern Germany.
The castle ruins are free to explore, but can only be accessed on foot.
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.