With an area of 25,784 sq. km (9955 sq. miles), Highland is the largest of Scotland's local government areas. Stretching from Appin on Loch Linnhe in the south to the northern tip of Caithness and from the island of Skye in the west to Strathspey in the east, Highland Council Area encompasses the North West Highlands of Scotland, some of the islands of the Inner Hebrides and a deeply indented fjord-like coastline. Bisected by the Great Glen Fault, within which lies the Caledonian Canal and Loch Ness, the area includes some of the oldest rocks in Scotland and a landscape dominated by mountain and moorland. Britain's highest mountain, Ben Nevis, rises to the east of Fort William near the southern end of the region. Less than 2.5 per cent of the land, mostly in Caithness and Easter Ross, is devoted to arable farming while more than 26 per cent comprises heather moorland and peatland. While the Gulf stream on the northwest coast creates a surprisingly mild climate, rainfall can vary from 2500mm (98½ inches) in the west to less than 500mm (19¾ inches) in the east. This is one of the least populated regions of Europe having less than 10 inhabitants per square kilometre, a consequence of the hard environment combined with land clearance and emigration during the 18th and 19th centuries. Inverness, however, is a fast growing commercial centre in addition to being the administrative centre of the council area. Other centres of population include Nairn, Fort William, Ballachulish, Kingussie, Newtonmore, Aviemore, Grantown on Spey, Fort Augustus, Dingwall, Beauly, Strathpeffer, Alness, Invergordon, Brora, Golspie, Helmsdale, Lairg, Dornoch, Tain, Wick, Thurso, Lochinver, Mallaig, Kyle of Lochalsh, Ullapool and Portree. Created in 1975 as Highland Region, the present single tier Council area dates from local government reorganisation in 1996.