To be privately owned
Mürzsteg Castle

Mürzsteg Hunting Lodge in Styria now serves as the summer residence of the Austrian Federal President.
History+
The origins of the lodge date back to 1869, when Emperor Franz Joseph I had a private hunting lodge built in his hunting grounds near Neuberg an der Mürz. The designs in Swiss style came from August Schwendenwein and Johann Romano. As the property soon proved too small, expansions were carried out in 1879 and 1903. For Empress Elisabeth, a separate riding path was created in 1883. Three years later, in 1886, the park around the hunting lodge was established, and a water pipeline was installed. After the final expansion, political meetings also took place, including the visit of Russian Tsar Nicholas II in 1903, during which the Mürzsteg Protocols on the future of the Balkans were signed.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: gt123456
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: 47.6771, 15.4921