Inside the Citadel the king even planned to build a royal palace. A dream which never came through, but a church was built within the Citadel as well as a prison, a windmill, Commandant's quarters and other houses.
Kastellet was in use during the Battle of Copenhagen in 1807. The worst blow in modern time to this historic site came when Germany invaded Copenhagen in 1940. The German troops landed right here at Kastellet and blew up one of the 17th century portals.
Today Kastellet is open to the public and many choose it for a stroll.