In 'The Scottish Castle' published in 1960 Stewart Cruden included brochs as amongst 'The Earliest Castles'. Of course this was 'tongue in cheek' but nevertheless these iron age structures deserve the appellation 'castle' and are unique to Scotland.
Some 500 or so brochs have been identified to date and many more, no doubt, are lurking beneath grassy mounds.
Brochs are confined to the highland region and the northern and western isles. Some score or so occur south of the highland line and these so called 'Lowland Brochs' have intrigued antiquarians for years. At the moment Torwood Broch, Stirling, is under investigation. There is evidence that some of these southern brochs were violently overthrown - with the finger of suspicion pointing at the Romans.
Brochs rise from a 15 ft thick base the upper walls being ‘galleried’ to reduce weight. There are no openings except for a single entrance passage secured with door checks and a draw-bar. The brochs rose as much as 30-40 feet and were probably roofed and thatched.
A staircase wound round the hollow, galleried walls.
Two of the most complete brochs are to be found at Glenelg namely Dun Telve and Dun Troddan. Dun Troddan was badly damaged in 1722 when its upper walling was removed to build the nearby barracks of Bernera, themselves now in ruin.
The most complete broch in Scotland is that on the island of Mousa in Shetland. All the brochs pictured are in the care of Historic Scotland.