The Scottish area is particularly rich in prehistoric remains, in some measure due to the fact that being a hilly and mountainous country large tracts of the surface have never been torn by the plough, nor suffered from the iconoclastic hand of the improver. Save for the effects of drainage, and some change in the character of vegetation arising from alteration of climate, much of the moorland country must have changed little in aspect since a remote past.

Among the various prehistoric structures in Scotland none is more remarkable than the broch. It does not occur out of Scotland, and neither its development nor period of occupation are generally understood.