A complex of wartime fortifications, the longest military defensive system in the world, was ordered by Hitler and built between 1934 and 1938. The bunkers with reinforced steel walls are interconnected by underground corridors and form what is believed to be the longest defensive system in the world.

In 2005 the fortifications were awarded with the prestigious certificate of the Polish Tourism Organization, as a tourism product called "Swinoujscie – a fortress on the islands".

Hitler's headquarters at Gierloz, known as Wolf's Lair, is one of the most sinister places in the region, but it attracts many tourists because of its recent historical associations.