Things to discover in France

From September 1943, forced labourers excavated a vast underground tunnel complex in Mimoyecques on the outskirts of Calais.

One of the dunes of Blériot-Plage, west of Calais, was crowned with a command post in the autumn of 1943. The coastal batteries of Waldam, Oldenburg, Bastion II, Fort Lapin, Sangatte and Lindemann were controlled from here.

During the Second World War, the Germans built an observation bunker between Zuydcoote and Leffrinckoucke on top of the dunes.

With the closure of the Saint-Quentin headframe in 1971, slate mining in Rimogne, France, ended.

The cobblestone section from Wallers to Hélesmes plays a starring role every year in Paris-Roubaix. But until a hundred years ago, wagons packed with coal thundered above the cobblestone strip.

After the First World War, the German army left dozens of bunkers behind in the French Illies, a village about 20 kilometers west of Lille.

With the dynamiting of the two blast furnaces of the Usine de Senelle, the last witnesses of the steel basin in Longwy, France, disappeared in the summer of 1991. Or almost everything.

A reinforced concrete headframe is all that remains of the Dutemple coal mine, which has operated for almost two centuries.