A round, dry-stone Iron Age house found mainly in the north and west of Scotland. Broch have a tapering profile and thick, usually hollow walls, which often contain galleries and cells.
A 'broch' has the following characteristics; it is a tower constructed of drystone masonry with double skinned walls surrounding a central courtyard and a single small and easily defensible entrance with no other openings. The space between the double skinned walls was utilised to provide both rooms and storage areas and to support steps leading to an upper wooden platform.
Any inhabitants would have lived on the ground floor, but have slept on wooden platform or gallery lining the upper part of the tower.
Generally it seems that the entrance passage was deliberately constructed low so as to make that much harder for any assailants to storm the broch and catch the defenders unawares, and some display evidence of guard cells built into the passage way together with smaller cells believed to be for guard dogs.
Finally, the brochs were probably roofed, probably with thatch but possibly with animal skins or some other material.
Essentially they were primitive castles, a single round stone tower with a roof, ranging in height from 10 feet (3 metres) to the highest known at Mousa in the Shetlands, is 43 feet (13 metres) high.
What were they used for?
One theory is that they were not intended to operate as permanent living quarters but rather as a temporary home providing protection from raiding parties. They were essentially places of refuge where the local inhabitants and some of their more valuable livestock, and may also have served as observation points.
Others argue that as brochs are often in locations more convenient for activities like farming and fishing, when there were better situated defensive locations nearby, they may well have served as permanent homes, inhabited by the local lord or chieftain.
But like all forms of human endeavour they may also have served as tangible symbols of the wealth and power of the local chieftain.
Who built them?
They were constructed within the territories of the Celtic tribes later known by the collective name of Pict but such is the lack of knowledge of the times that it is impossible to ne more specific than that. It has even been suggested that there was a roving band of expert broch architects seeking design and build commissions from local tribal groupings.
When were they built?
It is difficult to date brochs, but the consensus of opinion is that most brochs were built in the period 200 BC to 100 AD but that sometime around the mid second century both construction and maintenance stopped and existing brochs were effectively abandoned.
There is no clear evidence as to why brochs were abandoned, either the perceived threat had gone or had became of such a nature so as to render them useless. It is likely that the answer has something to do with the nature of the relationship established between the Picts and the Roman authorities of Britannia.
Where can they be found?
As indicated above, although there are examples of similar stone fortifications in Wales, Scandinavia and Ireland the broch with its double skinned walls and constructed in a concentric circle is unique to Scotland. Around five hundred examples are known to have survived, concentrated in the north and north-west of Scotland with a few scattered examples in the south.
The best preserved tend to be in the remoter locations (where they were the least likely to pillaged as a source of building material);
There is also Edinshall
, but that, apparently may not be a 'real' broch.
* From the Thesaurus of Monument Types maintained by the Royal Commission on the Ancient and Historic Monuments of Scotland quoted at http://www.mda.org.uk/conference2001/pub32.htm
The entry for broch at
The article Brochs: More Questions than Answers?