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:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.