Luxembourg, listed on the Unesco list, was the largest fortress of the Habsburgs. A large part of the defensive walls were demolished, but fortunately the medieval fortifications and bastions from the 17th and 18th centuries in the eastern part of the city have survived in good condition. Visiting the mighty fortifications on the Alzette River, I felt completely lost by their size and dimensions. The only thing that remained in my memory was the Dent Creuse tower, a relic of a fortress built in the 10th century by Count Siegfried.