Sutherland has many rugged mountains such as Ben Hope, the most northerly Munro, and Ben More Assynt, the tallest peak in the county at 998 m (3,274 ft). The western part comprises Torridonian sandstone underlain by Lewisian gneiss. The spectacular scenery has been created by denudation to form isolated sandstone peaks such as Foinaven, Arkle, Cùl Mòr and Suilven. Such mountains are attractive for hill walking and scrambling, despite their remote location. Together with similar peaks to the south in Wester Ross, such as Stac Pollaidh, they have a unique structure with great scope for exploration. On the other hand, care is needed when bad weather occurs owing to their isolation and the risks of injury.