The remains of the Castle can be visited
Wartenstein Castle (Ruin) (Lauperswil)

The Wartenstein ruin in Lauperswil, Canton Bern, was a medieval castle complex. Situated on a narrow mountain ridge and surrounded by moats, it offered its inhabitants in the Emmental protection and a wide view over the landscape.
History+
The exact construction date of Wartenstein Castle in the 13th century is not certain. From 1228, the knights Swaro von Wartenstein are mentioned as owners, possibly descendants of the Lords of Rüderswil. In 1284, Knight Heinrich Swaro von Wartenstein, the last of his family, sold the castle and lordship to Trub Monastery, but continued to manage it as a fief. After his death in 1288, the property passed to Werner von Schweinsberg. During the Burgdorf War in 1383, the Bernese conquered and destroyed the castle.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 46.9711, 7.7331