The Cairngorms siteis located near Aviemore in Speyside. The site lies on the North-Western flank of the Cairngorms encompassing the catchment of the Allt a' Mharcaidh. It is part of the Invereshie and Inshriach National Nature Reserve, within the Cairngorms National Park, and covers some 10 km2. The site is in the UK's sub-arctic zone and is an important link to other upland ECN and to sites in the Alps and Pyrenees (GLORIA network) and also to networks across the Arctic (SCANNET and INTERACT). The site is ideally placed to monitor changes in tree colonisation, hydrology, pollution and vegetation change. The Cairngorms site has been used intensively for research since the 1970s. An Automatic Weather Station (AWS) has been operating at the site since 1984 and was used in the Surface Water Acidification Programme from 1984 to 1994. CEH and MI have used the site for long-term hydrological and snow studies for about 15 years. From 1997-1999 it was one of the ECOMONT (land use change in mountain areas of Europe) sites. Researchers at several universities and institutes use the site for vegetation, soils and nutrient cycling studies. The site forms part of the larger Feshie catchment in the NICHE programme (National Infrastructure for Catchment Hydrology Experiments).