Dolbadarn Castle is a fortification built by the Welsh prince Llywelyn the Great during the early 13th century, at the base of the Llanberis Pass, in northern Wales. The castle was important both militarily and as a symbol of Llywelyn's power and authority. The castle features a large stone keep, which historian Richard Avent considers the finest surviving example of a Welsh round tower. In 1284 Dolbadarn was taken by Edward I, who removed some of its timbers to build his new castle at Caernarfon.
The remaining parts of the castle continued to be used as a manor house into the 14th century. By the 18th century, however, Dolbadarn Castle was ruined and uninhabited. From the 1760s onwards, however, it became a popular topic for painters interested in the then fashionable landscape styles of the Sublime and the Picturesque. J. M. W. Turner's 1800 work Dolbadarn Castle depicted the back-lit castle looming over the landscape and became particularly famous, but the paintings of the castle by Richard Wilson and Paul Sandby also represent important artistic works of the period.
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.