To be privately owned
Süßenbrunn Castle

In the 22nd district of Vienna, Donaustadt, in Austria, is Süßenbrunn Palace. It has a U-shaped layout with hip roofs and a central main tower.
History+
The first documented mention of the estate was in 1320 as a fortified house, which was taken over by Dietrich von Pillichsdorf. After the Turkish Wars around 1529, the fortified house fell into disrepair. In the late 16th century, the area was re-settled by Urban Sueß, and a palace was built, with the current place name combining the family name and the old dominion name.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Schloss_S%C3%BC%C3%9Fenbrunn_01_.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: 48.2788, 16.4944