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

In the hamlet of Strahlegg in the Swiss Prättigau/Davos region, the Strahlegg Ruin, a castle complex, is located on a small hill. Its location on the old Prättigau trail and the well-preserved building fabric make it a testament to medieval architecture in Graubünden.
History+
The origins of Strahlegg Castle are not documented by written sources. Archaeological finds from 1965 indicate its use between the 13th and 15th centuries. In the 14th century, the castle was owned by the Straiff family, who likely held it as a fief from the Barons of Vaz. After the death of Ursula von Straiff in 1403, the castle, which had previously been unlawfully occupied by locals, was awarded to Count Friedrich von Toggenburg. Whether he asserted his claims remains unclear. Around 1550, Ulrich Campbell already described the complex as a ruin. Preservation work was carried out in several phases starting in 2006 to protect and consolidate the remaining structure.
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: 46.9162, 9.7553