Alensberg Castle, locally known as Château d'Alensberg, lies in a private garden west of the village of Moresnet, in the Liège province in the Wallonia region in Belgium.
Alensberg Castle was built in the mid 15th century by a Jean d'Alensberg in the valley of the Geul river. In the early 16th century the castle was in the hands of the Tzevel family, who also owned Eyneburg Castle.
Through marriage the castle went to the Dobbelstein family until the early 17th century when it went to the Straeten family. They owned it until the early 18th century. Later it was owned by Charles James Cockerill.
During World War I the Germans built a 1200 meters long and 58 meters high railway viaduct spanning the valley, for the transport of German artillery, only some 200 meters from the castle. During World War II the Germans blew up the viaduct during their retreat which also badly damaged Alensberg Castle. In 1946/47 the ruined extensions of the castle were demolished and the keep was restored in its medieval form.
At present the remains of Alensberg Castle are private property. It can not be visited. Too bad, I would have liked to view its interior.