The Rubh an Dunain promontory semi-broch is a classic site of its type. All that remains to be seen nowadays is a well built drystone wall, 3½ metres tall, that separates the level tip of the promontory from its hinterland. Probably walling was never required around its perimeter, as it is defended by sheer cliffs on all other sides.
You can read an extensive treatise on this site at Canmore.
To access the broch requires a delightful 5½ kilometre walk from the Glen Brittle Campsite, along the southern shore of Loch Brittle, mainly on well-defined paths. Stream crossing can be a problem in wet conditions, but on a sunny day the walk is most enjoyable.
After visiting the broch, further interest is afforded by the Chambered Cairn close to the northwest corner of Loch na h-Airde.
But the highlight of the day is certainly the return walk towards the Campsite, facing the Cuillin Mountains, surely one of the most scenic coastal excursions in Scotland.
Loch na h-Airde and the 'Viking Canal'
Immediately below the broch is an artificial channel 100 metres long that links Loch na h-Airde with the sea. Believed to date from the Viking era, this enabled small boats to harbour in the loch at high tide (mediaeval boat timbers were discovered on the northern edge of the loch in 2000 and 2008).
It's a fascinating story, which is related in detail at Canmore