To be privately owned
Varlar Castle

Varlar Castle in Rosendahl-Osterwick, North Rhine-Westphalia, originated from a former Premonstratensian monastery. Its history dates back to the 12th century.
History+
The origins of Varlar lie in a Premonstratensian monastery founded around 1123/24 by the Counts of Cappenberg. This monastery, based on a main estate in the rural community of Höven, benefited from Otto von Cappenberg's donation to the Premonstratensian Order. The monastery expanded its possessions, acquiring, among other things, the patronage over the church in Rhede. Economically, it was secured by the main estates of Varlar and Coesfeld and managed approximately 440 rented properties by the late 18th century. The Premonstratensians were involved in parish pastoral care, for example in Coesfeld and Rhede, and promoted agriculture. In the 16th and 17th centuries, the complex was damaged by looting.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://www.zeche.org/
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: 51.9862, 7.1794