The remains of the Castle can be visited
Valendas Castle (Ruin)

To the west of the village of Valendas in Surselva, Graubünden, Switzerland, lies the Valendas Ruin, a former castle on a steeply sloping hill.
History+
The Lords of Valendas, whose name is associated with the castle, were first documented in 1258. They were episcopal vassals and maintained connections with the Lords of Wildenberg and later with the Werdenbergers. The castle itself was first mentioned in 1332. An event occurred in the same year when Hainricus and Rudolf were killed in the castle, possibly in the context of the Vazerfehde.
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: 46.7881, 9.2767