To be privately owned
Kesselsberg Manor

On the southern outskirts of Duisburg in the Huckingen district is the Rittersitz Kesselsberg, a manor and estate. It sits on a small hill above the Sandmühle.
History+
The first documented mention of the estate, originally called "Hof auf dem Berge" (Farm on the Mountain), dates back to 1349. At that time, the Bergian Marshal Wennemar von Bottlenberg received the property from Margarete von Ravensberg-Berg as a lease. In the 15th century, it was renamed after its then-owners, the Lords of Bottlenberg called Kessel. A redemption of the hereditary rent to the Count of Berg was documented in 1434 and notarized in 1568. After destruction during the Thirty Years' War, the Rittersitz was rebuilt in 1646.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=564
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: 51.3538, 6.7466