The remains of the Castle can be visited
Hachen Castle (Ruin)

The Hachen ruin is a historic hilltop castle that rises on an elevation above the village of Hachen in the Hochsauerlandkreis.
History+
The origins of Hachen Castle lie around the year 1000, when it was built under Count Ezzo. In 1060, ownership passed to Otto von Northeim, whose wife, Countess Richenza, belonged to the Ezzonen family. Only twenty years later, in 1080, Otto's son, Count Kuno von Beichlingen, donated the complex to the Archbishop of Cologne. The latter, in turn, granted the castle as a fief to the Counts of Dassel. In 1232, the Counts of Dassel sold the castle to the Counts of Arnsberg. Through the sale of the entire county in 1368, the castle again fell to the Electorate of Cologne. Around 1371, Hachen Castle served as the dower seat of the last Arnsberg Countess Anna, who later preferred Wildshausen Castle.
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: 51.3797, 7.9811