The Valentine Submarine Dock is located on the border of Bremen, and it is one of the vital tourist attractions in it, as it contains the ruins of the shipyard and submarines of the German Navy in the period between 1943 and 1945 (that is, during the Second World War), it was the largest fortified boat facility in Germany , but it was damaged by air war raids, and today it is open for tours and visitors coming from different regions around the world.