Klusenstein castle was built in 1353 by Gerhard of Plettenberg, a vassal of earl Engelbrecht III of the Mark. The castle formed the boundary fortification of the earldom Mark to the bishopric state of Cologne and the earldom Arnsberg. All three territories met at the Hönne river valley, the castle was also overlooking an old road crossing the valley. During the feud between earl Engelbert and Gottfried IV of Arnsberg, the castle was under siege in 1366, but did not fall.
When the last earl of Arnsberg, Gottfried IV, sold the earldom to the bishop of Cologne, the castle lost its importance. Until the 17th century the family of Werminghausen owned the castle. During the 30 years war (1618-48) both Swedish and Hessian troops stayed in the castle. In 1695 the Brabeck family bought the castle, and was sold in 1812 to the Löbbecke family. In 1904 it was sold to the Hoesch company, and now belongs to the company Rheinkalk.
The castle is located on a 60m high cliff over the Hönne river valley, at around the narrowest part of the valley. At the bottom of the rock is a small cave in total 51m long. One corridor bends upward, but about 30m below the plateau it is blocked by stones. There were legends about a secret escapeway of the castle, in 2003 the top entrance to the cave was found below the eastern palais destroyed in 1840.
Below the castle is a mill, however though named Klusenstein mill it did not belong to castle. Since 1912 the railway connecting Balve and Menden runs directly below the castle.
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.