To be privately owned
Geiersberg Castle

At the northern edge of Friesach in Carinthia, Austria, Geiersberg Castle stands on a steep rocky outcrop. This complex, with origins dating back to the 12th century, is an example of medieval defensive architecture.
History+
The construction of Geiersberg Castle is estimated to have taken place around 1130, during the time of Salzburg Archbishop Konrad I. Its first documented mention was in 1271. From the 13th century onwards, the castle was closely associated with the Vicedom's office and served as part of the suburban fortifications. Following a fire in 1690, Johann Andrä Auer received the castle as a fief from Salzburg Archbishop Johann Ernst and had it restored. After several changes of ownership, the complex became uninhabitable from 1750.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.at/ktn/kaernten.html
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: 46.9563, 14.3990