Thunstetten castle manor was built as a country manor house in the Bernese Oberaargau in 1711 to 1713 or 1713 to 1715. The castle was built for the Landvogt Hieronymus von Erlach following plans by the architect Joseph Abeille. The castle remained with the Erlach family until 1746. From 1746 until 1971 it had numerous owners. In 1971 the Stiftung Schloss Thunstetten (Thunstetten Castle Foundation) took over management of the building and grounds. Today rooms in the castle or the entire castle can be rented for events or meetings.
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.