Coordinates: 57°40′34″N 7°03′58″W / 57.676°N 7.066°W South Lewis, Harris and North Uist NSA is a large National Scenic Area in the Western Isles of Scotland.
The designated area covers 109,600 hectares, including the mountainous south west of Lewis, all of Harris, the Sound of Harris and the northern part of North Uist.
North Harris contains Clisham (799m), the highest peak in the Outer Hebrides. Steep-sided glens, with precipitous crags, have a mountainous character. Exposure and grazing prevent tree growth. Deep sea lochs in the east penetrate far into the hills. The east coast of Harris has many bays and islets. The west coast has wide, sandy beaches with machair. Rocky headlands, separating the bays, have been sculptured into geos and stacks. Scattered islands lies in the Sound of Harris between South Harris and North Uist.
On North Uist the spectacular deep peatland supports a wide variety of vegetation and birds. Loch Maddy (Loch nam Madadh) is a unique fjardic sea loch. This network is one of the most extensive and diverse systems in Europe, combining both salt and fresh water. Loch nam Madadh supports an unusual combination of intertidal plants and animals. In some of the lagoons, fresh water organisms grow in a layer just above salt water organisms. Loch nam Madadh is a ferry terminal, a harbour for the creel fishing and is used for salmon farms.