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.
The Royal Palace was built in the first half of the 19th century as the Norwegian residence of King Charles III, who also reigned as king of Sweden and otherwise resided there, and is the official residence of the present Norwegian monarch. The crown prince resides at Skaugum in Asker west of Oslo. The palace has 173 rooms.
Until the completion of the Royal Palace, Norwegian royalty resided in Paleet, the magnificent town house in Christiania that the wealthy merchant Bernt Anker bequeathed to the State in 1805 to be used as a royal residence. During the last years of the union with Denmark it was used by the viceroys of Norway, and in 1814 by the first king of independent Norway, Christian Frederick.