Cwm Idwal is a spectacular hanging valley surrounded by some of the highest peaks in Snowdonia, serving as a classic example of a prospect dramatically sculptured by ice thousands of years ago.
Officially recognised in 1954 by the Nature Conservancy, Cwm Idwal was Wales’ first National Nature Reserve (NNR) and is a Site of Special Scientific Interest (SSSI). Encircled by towering high crags, screes, moraines and wind shattered rocks, it is one of the finest places to see how glaciation and post-glacial processes shaped our landscape. The cwm forms a magnificent amphitheatre behind the glacial lake of Llyn Idwal, where fresh water flows from mountain waterfalls.
The beauty of the area attracts thousands of visitors each year and according to a survey by the Radio Times in 2005, Cwm Idwal was ranked the 7th greatest natural wonder of Britain. Indeed, its fascinating geological features drew the famous nineteenth century naturalist Charles Darwin to the area.
The steep and brooding Clogwyn y Geifr (the Cliff of the Goat) and its rift, Twll Du (Black Hole), form a dramatic backdrop to the lake and are very popular with climbers, especially in winter.
In addition to attracting tourists, walkers, climbers and geologists, the valley is a destination for botanists. Uniquely, Cwm Idwal is the most southerly place in Britain to boast a variety of rare arctic-alpine plants. These include Moss Campion and a range of Alpine Saxifrages, such as Tufted Saxifrage and Snow Saxifrage. Most notably, it is home of the Snowdon Lily, a rare and protected species that can only be found in Britain on Snowdon and its surrounding environment.
The lake itself, with beds of reeds and horsetails, is home to cotton grass, mosses and the tiny sundew which catches insects in its leaves. Further up on the screes the parsley fern grows and on the ridges, tough plants endure the harsh, exposed conditions, these include Dwarf Willow and Stiff Sedge. For the bird enthusiast, this area is a great spot to view upland birds, such as the Ring Ouzel, Wheatear, Raven and Peregrine. Along with a thriving population of rare beetles, the area is also home to herds of feral goats.
The cultural significance of the valley is exemplified in the fabled origins of its title, with many believing the valley to be named after Idwal, son of one of the ancient Princes of Gwynedd. According to legend, Idwal drowned in the lake, and as a result of this, birds no longer fly above the waters.
There is a car park at Ogwen Cottage, located next to the A5 between Bethesda and Capel Curig, as well as Ogwen Car Park located within Bethesda.