The Fort Saint-Roch Museum, Maginot fort will introduce you to one of the most modern generations of fortifications.
Built between 1930 and 1934, it was designed so that 240 soldiers could live in wartime as if in a submarine, without seeing daylight for three months. Its four blocks go down to 28m below ground.
Mask required. Warm clothing recommended. ( 14 ° in the fort.)