Hanstholm fortress (German: Festung Hanstholm; Danish: Hanstholm batteri) was a large coastal fortification, which was built by Nazi Germany at Hanstholm in north-western Denmark during World War II. The fortress was part of the "Atlantic Wall" and its main purpose was to seal off the entrance to Skagerrak together with the Vara fortress in Kristiansand, southern Norway, as well as with the extensive minefields in Skagerrak. The fortress had a wide range of artillery, from medium-sized 17 cm guns up to four 38 cm S.K.C/34 guns, weighing 110 tonnes each (the whole gun position weighing 650 tonnes). The guns were protected by 3.5 metres (11 ft) of reinforced concrete and many anti-aircraft guns. The 38 cm guns were similar to the ones fitted to the Bismarck-class battleships and had been intended for Gneisenau. However, after Gneisenau was damaged in a bomb raid, a decision was made not to fit the guns to the ship, but to use them instead in fortresses. The guns could fire a 495-kilogram (1,091 lb) projectile 55 kilometres (34 mi), or an 800 kg (1,800 lb) shell 42 km (26 mi). The rate of fire was 1 shot per 1.5 minutes.