Irish: Abhainn Ghleann Crí
The Glencree valley is a glacial valley which lies at the north eastern edge of the Wicklow mountains. The Glencree river, which flows through the valley, is a good example of a fast flowing upland river with many boulders and often brown peaty coloured water.
The river valley includes three areas of deciduous woodland which flank the river. The main tree species in the woods is Oak (Quercus petraea), with Ash (Fraxinus excelsior) and Birch (Betula pubescens) locally abundant. The shrub layer in the woods is variable. Holly (Ilex aquifolium), Birch (Betula pubescens) and young Beech (Fagus sylvatica) are the most common species. The field layer is generally sparse, and includes Wood-sorrel (Oxalis acetosella), Bracken (Pteridium aquifolium) and Wood-rush (Luzula sylvatica). Mosses are fairly abundant – these form carpets over the boulders. The moss species include Polytrichum commune, Rhytidiadelphus spp. and Thuidium tamarascinum. In places Hazel (Corylus avellana) is common and here the field layer is more diverse with Bluebells (Hyacinthoides non-scripta), Ramsons (Allium ursinum), Dog Violet (Viola riviniana), Herb Robert (Geranium robertianum) and Germander Speedwell (Veronica chamaedrys). Patches of Willow (Salix spp.) are found in the wetter areas.
Regeneration in the woods is generally poor due to grazing. of the woods has taken place in some areas, notably with Hemlock (Tsuga heterophylla) and Scots Pine (Pinus sylvestris). On the south side of the river between the wooded areas there are species-rich boggy flushes with clumps of Sphagnum moss (Sphagnum spp.) and areas dominated by Sedges (Carex spp.) and Rushes (Juncus spp.). Other species include Bog Asphodel (Narthecium ossifragum), Butterwort (Pinguicula vulgaris), Devils-bit Scabious (Succisa pratensis), Milkwort (Polygala vulgaris) and occasional low hummocks of Heather (Calluna vulgaris), Bilberry Vaccinium myrtillis) and Cross-leaved Heath (Erica tetralix).
The bird life of the valley has been examined recently. Dipper and Grey Wagtail breed along the river, while Jay, Long-eared Owl, Woodcock and Blackcap are present in the woods.