The remains of the Castle can be visited
Hasensprung Castle (Ruin) (Pratval)

On a small hill on the western edge of the village of Pratval in the canton of Graubünden, Switzerland, is the Hasensprung ruin, a former hilltop castle. Despite its heavily overgrown state, its history likely dates back to the 13th century.
History+
Although written records regarding the origin and early years of Hasensprung Castle are scarce, it is believed that the tower was built in the 13th century. A mention in the urbarium around 1370 indicates its existence. It is presumed that the Barons of Vaz were the original owners before the castle passed to the Werdenbergers. An event in its history was its destruction in 1356 during the Schamserfehde.
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: 46.7314, 9.4439