area and the island council areas of Orkney, Shetland and the Western Isles. Highland Council signs in the Pass of Drumochter, between Glen Garry and Dalwhinnie, say "Welcome to the Highlands". Highlands and Islands Much of the Highlands area overlaps the Highlands and Islands area. An electoral region called Highlands and Islands is used in elections to the Scottish Parliament: this area includes Orkney and Shetland, as well as the Highland Council local government area, the Western Isles and most of the Argyll and Bute and Moray local government areas. Highlands and Islands has, however, different meanings in different contexts. It means Highland (the local government area), Orkney, Shetland, and the Western Isles in Highlands and Islands Fire and Rescue Service. Northern, as in Northern Constabulary, refers to the same area as that covered by the fire and rescue service. Historical crossings There have been trackways from the Lowlands to the Highlands since prehistoric times. Many traverse the Mounth, a spur of mountainous land that extends from the higher inland range to the North Sea slightly north of Stonehaven. The most well-known and historically important trackways are the Causey Mounth, Elsick Mounth, Cryne Corse Mounth and Cairnamounth. Courier delivery Although most of the Highlands is geographically on the British mainland, it is somewhat less accessible than the rest of Britain; thus most UK couriers categorise it separately, alongside Northern Ireland, the Isle of Man, and other offshore islands. They thus charge additional fees for delivery to the Highlands, or exclude the area entirely. Whilst the physical remoteness from the largest population centres inevitably leads to higher transit cost, there is confusion and consternation over the scale of the fees charged and the effectiveness of their communication, and the use of the word Mainland in their justification. Since the charges are often based on postcode areas, many far less remote areas, including some which are traditionally considered part of the lowlands, are also subject to these charges. Royal Mail is the only delivery network bound by a Universal Service Obligation to charge a uniform tariff across the UK. This, however, applies only to mail items and not larger packages which are dealt with by its Parcelforce division. Geology The Highlands lie to the north and west of the Highland Boundary Fault, which runs from Arran to Stonehaven. This part of Scotland is largely composed of ancient rocks from the Cambrian and