Dun Ardtreck is a D-shaped dun, or 'semi-broch', situated on a rocky knoll on the edge of a cliff overlooking the sea. It encloses an area of about 13 by 10 metres. It was constructed with a ruidmentary hollow-wall. The entrance is particularly well-preserved with door-checks characteristic of brochs. The entrance to a guard cell led off to the right behind the door-checks.
Dun Ardtreck was excavated by Euan W. MacKie in 1964-1965 as part of an exercise to establish the development of the broch. It had been built in two stages: a roughly level platform was constructed and on this was set the galleried wall. Charcoal from the platform was radiocarbon dated to 115 BC. The first phase of occupation seems to have been very short and it appears to have ended in violence and destruction. The second phase was dated from the pottery finds to the middle of the 2nd century AD. The finds from this period included iron tools, bronze ornaments and glass ring-heads as well as Roman Samian ware pottery sherds and a piece of a Roman bead.
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.