To be privately owned
Ehrnegg Castle

Southeast of St. Kollmann in the municipality of Griffen, Ehrnegg Castle, a Renaissance castle, rises on a hillside. The name "Ehrnegg" is derived from "Ährenfeld" (field of ears), while the Slovenian dialect name "Rzenegg" refers to a "Roggenfeld" (rye field).
History+
A place called "Arnek" was first documented in 1158. The current Renaissance castle was built in 1586 by Eberhard Erdtl von Haimstatt, the Bamberger administrator of Weissenegg. Around 1660, it came into the possession of Neidhart Julius Freiherr von Staudach. Franz Graf von Dietrichstein acquired the castle in 1670 and had the second floor redesigned in the early Baroque style. After further changes of ownership, including Graf Polykarp von Christallnigg and the Barons Kaiserstein and Egger, the complex passed to the Barons von Helldorf in 1886. In 1979, the Piskernik family acquired the castle and reconstructed the Baroque garden.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Schloss_Ehrenegg.JPG
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: 46.6863, 14.7687