Altena Castle in North Rhine-Westphalia by EuroTourData
Altena Castle is the restored spur castle, built around 1112 (not confirmed) for the Dukes of Berg in order to protect the iron industries. The castle contains the Mark County Museum (German: Museum der Grafschaft Mark). The owner of the castle is district Märkischer Kreis.
The article Burg Altena of German Wikipedia.