Château du Wasigenstein, Rock castle in Niedersteinbach, France.

Château du Wasigenstein is a medieval rock castle in Niedersteinbach, in the northern part of Alsace, made up of two separate ruins sitting on sandstone ridges. The two parts, known as Grand-Wasigenstein and Petit-Wasigenstein, are divided by a natural gap in the rock and each use the stone as a structural part of their walls and floors.

A castle existed here by 1270 and is documented around 1299, when only a small residential tower stood on the Petit-Wasigenstein rock. The site was enlarged from 1299 with a second castle on the western rock, making it a double castle. After the Wasigenstein male line died out in 1359, the property was split among heirs, and the castles were besieged eight times in the second half of the 15th century before being abandoned before 1500. Fire damaged the ruins in the Thirty Years War, and the Palatinate War of Succession completed their destruction.

The name comes from the rock the castle stands on, the Wasigenstein. The site is linked to the Waltharius legend: the narrow gap between the two castles is called the Walthersspalte, where Prince Walther is said to have fought Gunther's eleven knights. The nearby Zigeunerfels takes its name from seventeenth-century bandits.

The site is reached by a marked trail from the Klingelfels parking area, following the GR 53 route, with the walk taking around 15 minutes. The path gets steeper and rockier near the top, so good walking shoes make the final section much easier.

The site is tied to the Waltharius legend: the narrow cleft between the two rocks, called the Walthersspalte, is said to be where Prince Walther fought the eleven knights of Gunther. Its width allowed only single combat, and the story places the events in the 10th century.