To be privately owned
Hülsede Castle

Hülsede Water Castle, a four-winged complex in Lower Saxony, is an example of Weser Renaissance architecture.
History+
The origins of the estate date back to 1310, when the Count of Schaumburg enfeoffed the Rottorps with the farm in Hülsede, which formed the foundation of the later manor. Between 1529 and 1548, Claus von Rottorp constructed the current castle as a four-winged complex, with building continuing until around 1600. After the male line of the von Rottorps died out in 1584, disputes arose over the property.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=529
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: 52.2496, 9.3630