Steyregg Castle dates back to the late 11th century (a similar structure, most likely made from wood, was there already before the turn of the last millenium). After the castle had been hit by two fires in the 18th century the original architecture remained largely untouched afterwards.
The castle was carefully renovated and extended in 2004 and its splendid rooms can be rented for private events. Especially beautiful is the castle chapel (late 13th – early 14th century) with its magnificent gothic frescoes from the 14th century (redone in baroque style in 1680). Parts of Steyregg's former city walls are still in good condition.
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.