Carlow Castle has a large rectangular three-story limestone keep with circular towers at each angle. The castle dates from the early 13th century. It was built by William Marshal the elder in the time period between 1207 and 1213 which he spent in Ireland. The castle in Carlow was the very first of its kind in Ireland.
The castle was handed over to the crown in 1306, granted in 1312 to Thomas Plantagenet, confiscated by the crown in 1537 as the landlords were absent, bought by the Earl of Thomond in 1616, changed hands multiple times until it was taken by Oliver Cromwell in 1650 but was later returned to the Earl of Thomond. In 1814 the castle was widely destroyed in an attempt to create more space for the conversion into a lunatic asylum with the help of explosives. Just the outer face of the west wall and the two neighbouring towers could be preserved.
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.