The original Hainewalde water castle, built under rule of the family von Nositz, was located north of the terraces of the new castle. The only remain of the old water castle, which was demolished in 1780, is the gate lodge with his west-side Renaissance-portal. Schloss (New Castle) was constructed in 1750–1753, along with its Baroque gardens, under the rule of the Kanitz-Kyaw family. It was renovated in 1883, the Baroque elements on the outside façade removed and replaced by 'Italian'-style sgraffito.
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.