Kastelburg castle was built between 1260 and 1270 by the Lords of Schwarzenberg. Like the Schwarzenburg on the opposite side of the valley its purpose was to defend the town Waldkirch and to control the trade route through the Elz valley.
The first inhabitant of the castle was Johann I of Schwarzenberg. The Schwarzenbergs died out already in 1345 and the castle was sold to Martin Malterer from Freiburg who fell in 1386 in the Battle of Sempach. In 1429 the castle was passed on to Berthold of Staufen.
In the Thirty Years' War the castle was destroyed by troops of the Kaiser on 14 March 1634 so that it did not fall into the hands of the advancing Swedish troops.
In recent years attempts have been made to conserve the edificial structure of the ruin that is standing romantically above the historic center of Waldkirch.
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.