To be privately owned
Schede Manor

In Herdecke, Haus Schede is a historic manor and estate, with origins tracing back to the 9th century. Situated on a hill in the Ardey Mountains, it is connected to the Harkort family, who influenced the industrialization of the region.
History+
The earliest mention of the estate dates to the 9th century. An existing farmhouse from the 17th century was inhabited by Judge Reinermann from 1640 onwards. From 1748, the family of industrialist Peter Harkort took ownership of the estate. They played a role in establishing iron and steel production in the Ruhr area. The current manor house was built in 1810 from Ruhr sandstone. In the early 20th century, the interiors were redesigned by architects Henry van de Velde and Peter Behrens, facilitated by Karl Ernst Osthaus. The estate remains in the possession of the Harkort family to this day.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Roland Neubert, Halle (Saale)
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: 51.3947, 7.3833