Clogwyn Du'r Arddu

The great cliff of Snowdon, Clogwyn Du'r Arddu, known affectionately as Cloggy, is a dark, brooding crag high on the flanks of Wales's highest mountain, widely regarded as the finest mountain rock cliff in Britain and a place of near-mythic status among trad climbers.

The rock is rhyolite, and the climbing is serious traditional multi-pitch on steep, often intimidating walls and slabs, with leader-placed protection. Cloggy holds a central place in British climbing history, the setting for landmark ascents across generations that pushed the sport forward, and its routes range from classic mid-grade lines to hard, bold Extremes. The East Buttress and West Buttress give contrasting steep and slabby adventures, all demanding real commitment and a cool head.

The setting is high and wild: a north-facing amphitheatre above the small lake of Llyn Du'r Arddu, reached by a long uphill walk, sometimes alongside the Snowdon mountain railway. The altitude, shaded aspect and seepage mean the crag is slow to dry and can feel remote and committing despite the mountain's popularity with walkers thronging the summit paths above.

Summer is the season, roughly late spring to early autumn, when the north-facing rock finally dries and the days are long enough for a big route and the walk out; even then it needs a settled dry spell. Llanberis at the foot of the mountain provides lodging, gear shops and cafes. For experienced trad climbers, Cloggy is a coveted, atmospheric mountain prize worth waiting for.