To be privately owned
Achternberg Manor

Haus Achternberg is a former manor and estate house located in the Kray district of Essen. The complex, whose origins date back to the Middle Ages, was once a knight's estate.
History+
The presumably two-part complex came into the possession of the von Arbeck family in 1421. In 1638, ownership transferred within this family to Johann Sigismund von Arbeck und zum Hardenberge. In the 18th century, the Barons von Wendt were the owners, enfeoffed with the estate in 1715. A record from 1721 in their estate documents attested to the poor condition of Haus Achternberg and ordered its reconstruction. In 1905, the estate was largely destroyed by fire.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=575
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: 51.4836, 7.0847