To be privately owned
Ottenfeld Castle

In Alsdorf-Duffesheide, Ottenfeld Castle, also known as Ottenfeld Estate, is a historic manor house with an associated farm. It is one of the oldest estates in the region.
History+
The first documented mention of Ottenfeld Estate occurred in 1420 in the Weistum of the Lordship of Alsdorf as a Kurmutgut. Around 1500, the property was owned by the Aachener Kreuzherren, who had it managed by tenants. In the 17th century, the estate passed to the baronial family von Blanckart, who also owned Alsdorf Castle. At that time, Ottenfeld was a Rhenish country estate in the form of a closed four-winged complex. In the early 19th century, ownership changed, before Josef von Blanckart, the brother of the then owner of Alsdorf Castle, reacquired the estate for his family in 1846. His son Karl initiated the construction of a new castle-like residence in 1878, after which the property became known as Ottenfeld Castle.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.wehrbauten.de/thread.php?threadid=845
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: 50.8630, 6.1396