Dudelange Castle, locally also known as Burg Düdelingen, Château du Mont Saint-Jean or Burg Johannisberg, is situated on an 80 meter high hill, west of the village of Budersberg, north west of the town of Dudelange in Luxembourg. The hill is named Mont Saint-Jean (in French), Johannisberg (in German) or Gerhaansbierg (in Luxembourgish) because of the small church dedicated to John the Baptist which has been an important place of pilgrimage.
It is not known when the first castle at this site was built. Archeological excavations showed Gallo-Roman use of this site.
The present ruins of Dudelange Castle date back to the beginning of the 15th century. It was built by the Lords of Gymnich after a predecessor, which stood in the town of Dudelange itself, was destroyed. The succeeding owners; the Lords of Boulay, Neufchâtel, Hunolstein and Isenbourg, all strenghtened and embellished Dudelange Castle. The castle was known as an impressive castle which hosted famous feasts.
After 1542 Dudelange Castle was damaged considerably when it was conquered and reconquered several times during the war between the Kings of France; Francois I and Henri II, and Charles V. In 1552 it was finally destroyed by French troops and lost all its strategic value. From then on the ruins of Dudelange Castle were used as a quarry for building material for surrounding villages.
At present the ruins of Dudelange Castle are freely accessible. There is also a modern watch tower between the church and the castle ruins to get a good view of the entire site although it was closed when I visited. The castle ruins were also closed when I visited because of archeological excavations. They were also very much overgrown. It is a nice site although it is hard to imagine how it must have looked. So the ruins might not be very impressive but the steep walk uphill to the castle is very nice.