Arkle is a mountain

Mountain

Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...

 in Sutherland

Sutherland

Sutherland is a registration county, lieutenancy area and historic administrative county of Scotland. It is now within the Highland local government area. In Gaelic the area is referred to according to its traditional areas: Dùthaich 'IcAoidh , Asainte , and Cataibh...

, situated in the far north-west corner of the Scottish Highlands

Scottish Highlands

The Highlands is an historic region of Scotland. The area is sometimes referred to as the "Scottish Highlands". It was culturally distinguishable from the Lowlands from the later Middle Ages into the modern period, when Lowland Scots replaced Scottish Gaelic throughout most of the Lowlands...

. Like its sister Foinaven

Foinaven

Foinaven is a mountain in Scotland, situated in the far north-west corner of the Scottish Highlands. Like many of the monolithic mountains that surround it, the mountain is within the Moine Thrust Belt and is made up of imbricated layers of Cambrian quartzite which overlie the older Lewisian...

, the mountain is made up of glistening white Cambrian

Cambrian

The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

 quartzite

Quartzite

Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...

, laid down around 530 million years ago on an uneven basement of much older Lewisian gneiss

Lewisian complex

The Lewisian complex or Lewisian Gneiss is a suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland, forming part of the Hebridean Terrane. These rocks are of Archaean and Paleoproterozoic age, ranging from 3.0–1.7 Ga. They form the basement on which the...

. The quartzite, and the Torridonian sandstone which makes up many of the other mountains in the area, have been dissected by rivers and glaciers, leaving a series of isolated peaks, such as Suilven, Quinag

Quinag

The mountain Quinag in Sutherland, in the Scottish Highlands, is in fact a mountain range with an undulating series of peaks along its Y-shaped crest...

 and Stac Pollaidh

Stac Pollaidh

Stac Pollaidh is a mountain in the Northwest Highlands of Scotland. The peak displays a rocky crest of Torridonian sandstone, with many pinnacles and steep gullies. The crest is extremely weathered , suggesting that it was not covered in ice during the last Ice Age.The name Stac Pollaidh is often...

, standing above the "knock and lochan" landscape of small hills and lakes that is typical of the Lewisian gneiss.