Grey Mare's Tail Nature Reserve is situated along the Moffat Water Valley in the heart of the Southern Uplands. This National Trust for Scotland property extends over 922 hectares and is characterised by a dramatic waterfall (the 5th highest in the UK), an upland loch Loch Skeen and White Coomb which rises to 821m and is one of the highest hills in Southern Scotland. The post-glacial landscape is an open mosaic of heather and rough grazing that includes 8 habitats of European importance and many plant species of international, national and regional significance. The reserve is botanically diverse, containing the richest assemblage of rare upland plants in Southern Scotland.