Coordinates: 57°30′N 5°0′W / 57.500°N 5.000°W The Northwest Highlands are located in the northern third of Scotland that is separated from the Grampian Mountains by the Great Glen (Glen More). The region comprises Wester Ross, Assynt, Sutherland and part of Caithness. The Caledonian Canal, which extends from Loch Linnhe in the south-west, via Loch Ness to the Moray Firth in the north-east splits this area from the rest of the country. The city of Inverness and the town of Fort William,
The Highlands are formed on Lewisian gneiss, the oldest layers of rock in Scotland. Liathach, Beinn Alligin, Suilven, Cùl Mòr, Cùl Beag, and Quinag are just some of the impressive rock islands of dark red Torridonian sandstone which rests on the gneiss, being the younger rock. Some of the peaks, such as Beinn Eighe and Canisp, are topped with later light grey or white Cambrian quartzite. The gneiss, sandstones and quartzite are among the oldest rocks in the world.