Dun Beag (the small fort) is the best known, best preserved and most accessible broch on Skye. Brochs are unique to Scotland - they were probably defensive homes, though no one is sure, and were built about 2-2,500 years ago. Dun Beag is situated just north of Struan, to the east of the road - there is a small car park and you will need stout footwear and lungs for the sort walk uphill to look at it. The distinctive double walls are more or less intact to about 6 feet - originally it would have stood about 30-40 feet high. The views are wonderful. The rubble of Dun Mor (the big fort) is less than 1/2 mile further on - take a map.
Post code for Dun Beag is very approximate - look for signs.