The Lowther Hills, also sometimes known as the Lowthers, are an extensive area of hill country in the Southern Uplands of Scotland, though some sub-ranges of hills in this area also go under their own local names - see Hillwalking below. They form a roughly rhomboidal or lozenge shape on the map with the acute angles being to north and south. It has river valleys along its boundaries to north east (Clydesdale) and south west (Nithsdale) which carry the two largest arterial routes northwards into the west side of the Central Belt of Scotland. A string of small towns have long since developed along these routes. Most of the Lowther Hills lie in the Administrative County of Dumfries and Galloway, though part in the administrative county of South Lanarkshire moves into them around the village of Leadhills and the Daer Reservoir.