Alte Burg, 'The old castle', in Burgsinn is a moated castle owned originally by the Barons of Thüngen. In 1337, the Bishop of Würzburg granted the castle and all its possessions as a fief to Dietz von Tungden, who largely built the present castle between 1339 and 1342.
The wide moat surrounding the castle is fed by an underground spring. On the west side, a bridge leads into the castle, which has a trapezoidal layout with towers at its corners. The outer wall is made of rusticated sandstone blocks, while the rest of the masonry is rubble stone, and the southern residential building features timber framing on its upper levels.
The square northeastern tower includes a small elevated residence. A pointed arch door leads into the southeastern tower, which was completed in 1543 by Martin I von Thüngen. The southern wall has been significantly altered with inserted windows, and the round-arched gate at the southwestern tower was fitted with corbels.
The castle complex is dominated by a square, five-story, 22-meter-high keep (dating to the 12th century), constructed of rusticated stones.
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.