Outer Hebrides - Geography

Geography

The main islands form an archipelago of which the major islands include Lewis and Harris, North Uist, Benbecula, South Uist, and Barra. Lewis and Harris has an area of 217,898 hectares (841 sq mi) and is the largest island in Scotland and the third largest in the British Isles, after Great Britain and Ireland. It incorporates Lewis in the north and Harris in the south, both of which are frequently referred to as individual islands, although they are joined by a land border.

The largest islands are deeply indented by arms of the sea such as Loch Ròg, Loch Seaforth and Loch nam Madadh. There are also more than 7,500 freshwater lochs in the Western Isles, about 24% of the total for the whole of Scotland. North and South Uist and Lewis in particular have landscapes with a high percentage of freshwater and a maze and complexity of loch shapes. Harris has fewer large bodies of water but innumerable small lochans. Loch Langavat on Lewis is 11 kilometres (6.8 mi) long, and has several large islands in its midst, including Eilean Mòr. Although Loch Suaineabhal has only 25% of the Langavat's surface area it has a mean depth of 33 metres (108 ft) and is the most voluminous on the island. Of Loch Sgadabhagh on North Uist it has been said that "there is probably no other loch in Britain which approaches Loch Scadavay in irregularity and complexity of outline." Loch Bì is South Uist's largest loch and at 8 kilometres (5.0 mi) long it all but cuts the island in two.

Much of the western coastline of the islands is machair, a fertile low-lying dune pastureland. Lewis is comparatively flat, and largely consists of treeless moors of blanket peat. The highest eminence is Mealisval at 574 m (1,883 ft) in the south west. Most of Harris is mountainous, with large areas of exposed rock and Clisham, the archipelago's only Corbett, reaches 799 m (2,621 ft) in height. North and South Uist and Benbecula, (sometimes collectively referred to as The Uists) have sandy beaches and wide cultivated areas of machair to the west and virtually uninhabited mountainous areas to the east. The highest peak here is Beinn Mhòr at 620 metres (2,034 ft). The Uists and their immediate outliers have a combined area of 74,540 hectares (288 sq mi). Barra is 5,875 hectares (23 sq mi) in extent and has a rugged interior, surrounded by machair and extensive beaches.