Christiansholm Fortress was finished in 1672 and formed a part of King Christian IV's plan for defense of Kristiansand when the city was founded in 1641. The architect of the fortress was quartermaster general Willem Coucheron. It was built on an islet, about 100 yards from shore. Today the fortress is connected to the mainland.
The only time the fortress has been in battle was against an English fleet force, lead by HMS Spencer (1800) in 1807 during the Napoleonic Wars. It was decommissioned by royal decree during June 1872 as part of a major redevelopment of fortifications across the nation.
Today, Christiansholm is a tourist attraction by the Kristiansand Boardwalk and venue for a variety of cultural events and festivities. It is now owned by the municipality and is a site used principally for recreation.
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.