Trondenes Fort is a fort situated on Trondenes peninsula near Harstad in the Norwegian county of Troms.
It has been the main base for the Norwegian Coastal Ranger Command since 2002. The fort was built in 1943 by the Nazis occupying Norway during World War II as a part of the Atlantic Wall.
It was equipped with four of the world's largest land based guns (40.6 cm). The guns were taken out of the Norwegian mobilisation plans in 1961, but are still in place and one is kept in working order for conservation purposes. The guns are 40.6 cm Schnelladekanone C/34, sometimes known as the Adolfkanone, Adolf Guns and have a barrel length of 20.3 metres. The standard shell weighed 1030 kg with a range of ca. 43,000 m, while the lighter 600 kg shell had a range of 56,000 m. As a part of the Atlantic Wall the fort is unique in its original set up and high degree of preservation.