Salnecke is one of the best preserved 17th century castles in Uppland. The first known owner of Salnecke was a judge Karl Ingeborgasson Lejonbalk. He sold the farm to the Skokloster nunnery in 1302. Later it belonged to Bo Jonsson Grip and the monastery of St. Clare in Stockholm. The monastery was the owner until 1460, when Salnecke fell to archbishop Jons Bengtsson (Oxenstierna).
After Reformation Salnecke became a crown property. Gustav II Adolphus gave the farm to the council Filip Sadler in 1626. After his death in 1641 Salnecke was given to Grissbach. The castle belonged to his family until 1730's. Salnecke was acquired by Klas Samuel Jonas Gyllenadler in the 1830s and it is still in his family's possession.
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.