Broch

A prehistoric circular towerlike building of dry stone which was peculiar to the north and west of Scotland. The hollow walls, which contained chambers and stairways, were built of dry masonry and the tower was usually 13-20 m in diameter and tapered inwards in the upper courses. The walls may be up to 20 feet (4 m) thick. Over 400 are known in Scotland and the structures served as fortified homesteads. They originated in the mid-1st millennium BC, but most dated from the beginning of the Christian era. The Broch of Mousa on Shetland is the best preserved and most famous example. They are always in a strong defensive position, close to the sea.

A type of circular building found in north Scotland and the Isles from around the turn of the Christian era. Brochs were built of drystone walling, up to c4 metres thick; the brochs themselves may be up to 12 metres in diameter. They contained many chambers and stone stairways leading up to tiers of galleries above, and may have been fortified homesteads, since good arable land is usually to be found in the vicinity.