No other town or city in Europe has a fortress as large as this. Built on a rocky spur on the banks of the Meuse, it covers 35 000m2, has 7 floors and could house 4 000 troops. For five centuries, it occupied a strategic location between France and the German Empire and was continually strengthened over a period of 500 years. As you stroll through its maze of corridors and rooms, discover the secrets of its impregnable fortifications and stories of daily life in the principality of Sedan.