The Coupole, an imposing underground base, was built in 1943 to serve as the launchpad for firing V2 rockets at London. This vast bunker is one of the most impressive leftovers of World War II. Located 5 kilometres from Saint-Omer, this site is now a WWII museum (Centre d'Histoire de la Guerre et des Fusées), bearing witness to the dark years of the Occupation and the underside of the race to space. There are themed circuits to follow so as to better understand each stage of the tour. The planetarium provides a moment of relief from all this darkness, with a 360° film that launches you into outer space.