Early in the morning of 1th September 1939 the German battleship Schleswig-Holstein opend fire on the Polish positions at Westerplatte. Westerplatte was a Polish naval depot, there was located on a small island in the Free City of Danzig. This was the first shot that was fired in the secound World War.
On the Hela peninsula, 13 miles north of Danzig, the Germans began in 1941 to build a gun battery, with the name of Schleswig-Holstein. The battery should consisted of three406 mm. guns, nicknamed Adolf guns. These guns had, using a grenade at 1300 lb., A range of 34 miles. Standard grenade weight was 2200 lb. and here the range was 26 miles. The barrel was 70 ft. long and had a shelf life between 250 and 300 shots.
The guns were operational in 1942, but already here the German High Command decided to close down the gun battery and move the guns to Calais in northern France. Here the three guns became part of the Atlantic Wall in Gun Battery Lindemann.
In addition to the three gun bunker, the Germans also build ammunition bunkers and an eight-storey high fire command bunker.
source: www.battlefieldsww2.com