After a nice hike uphill through the forest you reach the ruins of castle Dudelange. Not much is left of this castle but it can be visited for free. The castle was completed in the early 16th century and destroyed in 1552. The first castle of Dudelange belonged to the Lords of Gymmich. This stranghold was destroyed by the troops of Robert de Bar around the year 1400. Works on a new fortified castle started at the beginning of the 15th century which was completed early int the 16th century. However the castle was besieged time and time again from 1542 when Francis I and Henry II of France were at war with Emperor Charles V. The final blow was givin in 1552 when the castle was destroyed and stripped from all military features.
Since the 1970s, the Friends of the History of Dudelange and Mont St. Jean have explored the ruins, discovering the foundations of several towers, the palace, living quarters, stables and outhouses. Three wells and a reservoir were partly unearthed. The ditches and the entrance to the castle can still be seen.