To be privately owned
Ernegg Castle

Ernegg Castle is located in the market town of Steinakirchen am Forst in Lower Austria. Originally a medieval castle, it was transformed into a palace in the 16th century.
History+
The origins of Ernegg Castle trace back to a fortress that was part of the Hofmark Steinakirchen, belonging to the Bishop of Regensburg. In the 16th century, renovations began: from 1527, Wolfgang von Oedt zu Götzendorf and his descendants erected a four-sided castle with a corner tower and an arcaded courtyard on the castle plateau. Reichart Streun von Schwarzenau continued the construction from 1596. Since 1656, the castle has been owned by the Counts Auersperg.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.at/noe/niederoesterreich.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: 48.0656, 15.0654