Karjohansvern was the main base for the Royal Norwegian Navy from 1819 to 1963. It was the site of the Navy Main Yard, Navy Air Plane Factory, Navy Museum, Navy Schools and the forts Norske Løve andCitadellet.
Naval District East (ØSD) based there was disbanded in 2002. The Museum, the Royal Norwegian Navy Band, a department of theNorwegian Defence Research Establishment and some of the Navy's school administration is still present. As of 2006 the entire base including 73 buildings has been given protected heritage status by the Directorate for Cultural Heritage in Norway. Karljohansvern is open to the public. Only Vealøs is still owned by the Department of Defence.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.