To be privately owned
Kotten Castle (Bösperde)

Kotten Castle in Bösperde is a manor house whose origins date back to the 13th century. Its current appearance is shaped by a 17th-century building, characterized by a combination of quarry stone and half-timbering, and is now a protected monument.
History+
The history of Kotten Castle began in the 13th century as a knight's estate, initially belonging to the lower noble family von Kotten, whose presence is documented until 1383. After the von Kotten family, the von Werninghaus family took over the property. In 1590, it passed to Caspar von Schwansbell zu Arden, and in 1623, Arnold von Freisendorf zu Opherdicke became the owner. Today, Kotten Castle is privately owned by the von Gemmingen family.
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: 51.4582, 7.7568