Kristineberg Palace in Kungsholmen was built around 1750 for the businessman R. Schröder. The palace was surrounded by parks and the property included a great deal of the surrounding land. In 1864 the property was bought by the Swedish Freemasonry and additional construction on the palace was made. Stockholm City bought the land in 1921 and started building the Kristineberg district, and today part of the palace is used as a school.
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.