Tellenburg Castle was built around 1200 by the Lords of Kien. After the Lords of Kien, the Lords of Wädenswil became the owners of the castle. They were followed by the Lords of Turn in 1312 and then later by the city of Bern. The original castle was expanded and repaired in the 13th or 14th centuries.
Under Bernese rule, the castle served as the administrative seat of the surrounding area until the creation of the Helvetic Republic in 1798. After 1798 it was used as a poor house. In 1885, the castle was gutted in a fire. It was never rebuilt and has slowly fallen into ruin.
Tellenburg Castle was built as an administrative center and toll station. Telle at beginning of the name likely comes from the German word for toll, Zoll, while burg simply means fortress.
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.