A Broch is an Iron Age drystone hollow-walled structure of a type found only in Scotland. Brochs include some of the most sophisticated examples of drystone architecture ever created, and belong to the classification "complex Atlantic Roundhouse" devised by Scottish archaeologists in the 1980s. Their origin is a matter of some controversy, and the theory that they were essentially defensive military structures isn't accepted by many modern archaeologists. They were almost certainly originally r… (More on Broch)