UK ECN and UK UWMN site. Lochnagar lies at an altitude of 785 m in the centre of the granite massif which comprises much of Balmoral Forest. Lochnagar is a corrie loch and lies below a north- east facing steep backwall which rises to the summit of the same name. The loch is 9.8 ha in area with its deepest point at 24m, and drains north-east into a tributary of the River Dee. Snow-melt comprises a major input to the loch which regularly freezes each winter. The precipitous catchment (91.9 ha) is composed of biotite granite, overlain in places by blanket peat, but dominated by bare rock with extensive fields of large boulders and coarse screes. The sparse moorland vegetation of the catchment is dominated by a community of stunted Calluna (heather) and Vaccinium (bilberry). The catchment is above the limit for summer sheep grazing in the region, and there is no evidence for any land-use change or active land management. Lochnager is classified as having moderate acid deposition.