Copenhagen Citadel is a well preserved fortress built in 1664 and was in use until the 1830s. During its later years it helped defend the city against the British in the Battle of Copenhagen (1807), It is constructed in the form of a pentagon with bastions at its corners.
During World War II, the Germans occupied the citadel and adjacent to the Commandant’s House in 1943 built a substantial concrete bunker in the former garden. The design is the standard command bunker R608. The bunker was only lighly used during the conflict but was used by Danish Forces as a command post during the Cold War.
Today, although parts of the citadel are still used by the military, the substantial part is a public park wherre the fine architecture can be admired. The bunker, however, is used by a veteran’s group and cannot be visited.