To be privately owned
Gleuel Castle

Burg Gleuel in Hürth-Gleuel is one of the oldest moated castles in the historic Kölngau. Its history dates back to the late Frankish period.
History+
The origins of Burg Gleuel are closely linked to a Salhof that King Zwentibold gifted to Essen Abbey in 898, indicating the age of both the castle grounds and the associated church site. In the mid-13th century, the complex came into the possession of the Cathedral Chapter. Gerard von Gluele, a vassal, fought alongside the people of Cologne against Archbishop Konrad von Hochstaden in 1260. In 1463, Schultheiß Heinrich von Gluwel signed the hereditary union of the archdiocese. Göddert von Gleuel led the Kölner Funken as a cavalry captain in the Burgundian War in 1474.
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: 50.8915, 6.8358