Biskops-Arnö was a palatial residence of the archbishop of Uppsala, built in the first half of the 1300s. After the Reformation it was left to decay and finally demolished in the early 1700's, when the present main building was erected. For nearly 200 years Biskops-Arnö was a seat of Colonel in the Royal Regiment.
In 1956 Biskops-Arnö moved to the foundation of the Association of the Nordic Institute, who placed there a Nordic education institute and a college. Biskops-Arnö is a great destination that offers both nature and culture. Make sure to visit the Gothic hall, a room with limestone player and grand pillars - a remnant of the old bishop's castle. Visiting groups can book a meal or coffee at Biskops-Arnö college who also have hostel during the summer.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.