V-weapons, V2, Le Coupole.
This bunker can be found 5km south of Saint-Omer in the town called Wizernes.
The Germans started the construction of this bunker (Dome), built for launching V2 rockets, in 1943 The plan was huge; there were underground facilities to make liquid oxygen, and there were generators to provide the place with electricity. There was even an underground railway station to bring in supplies, equipment and V2 rockets from Germany. The dome has a diameter of 72m, the walls are 5.5 meter thick and overall they used 55.000 tons of concrete.
Just like the bunker in Eperlecques, this bunker was attacked by the Allied air force. After the bombardments the Germans couldn't use there railroads and the roads around the complex. As result of the Allied bombings. The dome had moved slightly from its original foundation.
That was not the only result. After the Allies used new and heavier bombs, 'Tallboys', in September 1944, the complex was damaged so heavily that it was no longer operational and so the Germans evacuated the whole site.
In the bunker is now a museum located. You can see their website at the Links.
1x V2 launching bunker (Dome).