Hiltenburg Castle in the Upper Fils Valley stands on the strategically advantageous, 707-m-high conical mountain peak of the Schlossberg, overlooking Bad Ditzenbach. Up until the 16th century it was the seat of the Counts of Helfenstein. In 1516 it was destroyed by Duke Ulrich of Württemberg, who was passing through on his way from Blaubeuren to Stuttgart. A cannonball from the Hiltenburg happened to land in Ulrich's camp, and this caused the Duke, who was known for his extremely hot temper, to have his men burn down the castle. The extensive complex is at present undergoing renovation.
Two vaulted cellars have been excavated, and archaeological finds attest that the Hiltenburg site was already populated as far back as the Bronze Age (c. 1000 BC). From the observation platform of the Hiltenburg's tower hikers can enjoy magnificent views of the Upper Fils Valley.
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.