Somewhat hidden, only accessible via narrow streets, lies an enormous concrete block in the military port of Brest: between 1940 and 1944, the largest submarine repair yard ever was built here by the Todt Organization using forced labor. It was 330 meters long, 180 meters wide with 10 dry docks and 5 additional boxes for three submarines each. The bunker was hit by 80 air raids. Only a specially developed super-heavy bomb called Tallboy, weighing 5.4 tons, succeeded in breaking through the reinforced concrete corner, which was ultimately more than 6 meters thick. Even after the war, the structure proved to be indestructible and was and is ultimately still used by the French Navy. The facility is still a military area, and a visit is not possible (contrary to what the Internet says otherwise) (this is information from the gate guard). Above the military area, however, there is a narrow one-way street on the slope, the Route de la Corniche (in the direction of the bunker), from which you have a good view of the facility, the shipyards, modern warships moored there and the bunker itself. Thankfully, there is an accompanying footpath and cycle path along the fence and various parking bays as well as a car park next to the bunker, which also allows access to the stone beach. If you walk along the high fence on the Route de la Corniche, you will suddenly notice a familiar blue and yellow sign: the road is part of a French Way of St. James to Santiago de Compostela.