To be privately owned
Borg Manor (Werl)

The Borg Manor House in Werl is a two-story building with a double-flight grand staircase. The estate is protected as a historical monument, and its grounds are listed as an archaeological monument in the registers of the city of Werl.
History+
The first documented mention of Haus Borg dates back to 1244, when it was still a moated castle. Until the mid-15th century, the knight's estate was owned by the de Castro family, also known as "von der Borg". In 1440, Peter von der Borg sold the complex to Wilhelm Keygen. The estate was already divided at that time, as Wilhelm Keygen the Elder and his sons sold their share in Haus Borg to the Freseken family in 1468. The other part of the property came into the possession of Kaspar von Plettenberg in 1540 through the inheritance of Margaretha von Schenking. Since Johann von Plettenberg had already acquired the Freseken share in 1486, the property was reunited.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 51.5700, 7.8643