To be privately owned
Overbach Manor

Haus Overbach in Jülich-Barmen is a manor and estate house that served as a knight's seat. It is privately owned.
History+
The first documented mention of Haus Overbach as a knight's seat dates to 1341, although a Heinrich von Overbach was already named as the steward of Count Wilhelm von Jülich in 1334. Around 1415, the estate comprised 61 Morgen of land. In the mid-15th century, the Greyn family owned the property, and the cellar vaults still preserved today date from this period.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=570
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: 50.9422, 6.3064