The museum is housed in one of the four casemates of the Todt Battery (seventh largest development built by the German army during the Second World War). The German artillery attacked England from here, firing 380mm shells over a distance of up to 42km. Inside, see collections of uniforms and weapons; outside, there is a rare example of the German heavy railway gun, the "K5", which has a maximum range of 86km. Krupp built just 25 of them in 1942.