Blackhammer Chambered Cairn is a Neolithic cairn on Rousay. It is thought to date from around 3000 BC. The structure is a typical stalled cairn, with an interior divided into seven compartments by pairs of upright stone slabs. The cairn has a modern roof, as the cairn originally was only a few feet high. Access is by a hatchway and ladder in the roof, as the original entrance was sealed. There have been finds of bones and pottery in the cairn.
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.