Few of the massive military structures built by Germany during World War II are as impressive as the U-Boat bases and bunkers in Germany, Norway and France. This title takes a close look at the formidable edifices on the French coast (Brest, Lorient, St Nazaire, La Pallice, Bordeaux) in Norway (Bergen, Trondheim) and in Germany (Keil, Hamburg, Helgoland) and also focuses on the huge 'Valentin'…