The Aragonese Alfonsino Castle, best known as Forte a Mare ('Sea Fort'), was built by King Ferdinand I of Naples in 1491 on the S. Andrea island facing the port of Brindisi. It is divided into two sections: the 'Red Castle' (from the color of its bricks) and the more recent Fort.
The castle was besieged by Venetians in 1529 and French army in 1799. It was damaged by storm in the modern age and was abandoned in 1984.
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.