Erstavik estate was first mentioned in 1356 when it was given to Bengt Larsson. It was acquired by Petersen family in the 18th century and his descendants still own the castle. In the Great Northern War 1719 Russian fleet persecuted also Erstavik and several farms were burned down. The current main building is designed by Jean Eric Rehn and it was build in the 1760s. The three-storey house includes an chapel and two wings. interior is well-preserved sample of Rococo and Gustavian style.
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.