Dun Ara was a stronghold of the MacKinnon clan who held the land here from 1354 onwards. The castle was still in use until the 17th century when it was abandoned. The castle was probably built on the site of a previous Dun or fort. The castle had a surrounding wall protecting a central keep or building on the main outcrop of rock. The location was valuable as it protected a harbour of boat landing as well.
The castle was fortified by enclosing the entire rock summit with a curtain-wall of stone and lime, which varies from about 1.3 m to 1.8 m in thickness. It is best preserved on the north-east side, where it rises to a maximum height of 1.8 m, but little remains on the south-west and south-east sides. The masonry was built with coarse, lime mortar, much of it has washed out of the facework giving it the appearance of dry-stone walling. It is possible that in places the lower courses of masonry pre-date the medieval castle and belong to an earlier fort that occupied the same site. The entrance is on the south-east side.References:
The Externsteine (Extern stones) is a distinctive sandstone rock formation located in the Teutoburg Forest, near the town of Horn-Bad Meinberg. The formation is a tor consisting of several tall, narrow columns of rock which rise abruptly from the surrounding wooded hills. Archaeological excavations have yielded some Upper Paleolithic stone tools dating to about 10,700 BC from 9,600 BC.
In a popular tradition going back to an idea proposed to Hermann Hamelmann in 1564, the Externsteine are identified as a sacred site of the pagan Saxons, and the location of the Irminsul (sacral pillar-like object in German paganism) idol reportedly destroyed by Charlemagne; there is however no archaeological evidence that would confirm the site's use during the relevant period.
The stones were used as the site of a hermitage in the Middle Ages, and by at least the high medieval period were the site of a Christian chapel. The Externsteine relief is a medieval depiction of the Descent from the Cross. It remains controversial whether the site was already used for Christian worship in the 8th to early 10th centuries.
The Externsteine gained prominence when Völkisch and nationalistic scholars took an interest in the late 19th and early 20th centuries. This interest peaked under the Nazi regime, when the Externsteine became a focus of nazi propaganda. Today, they remain a popular tourist destination and also continue to attract Neo-Pagans and Neo-Nazis.