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Cwm Idwal Mountain scramble and Rock Climb Snowdonia

Cneifion Arête 140m D/SG3 (1905)
This fantastic mountaineering line has all the qualities of a classic: unrivalled position high above Cwm Idwal, an atmosphere out of all proportion to its size, and the feel of an alpine ridge.


The lower section is quite steep, above this the upper ridge is enjoyable scrambling; exposed but with belays when required.


Start at the foot of the arête, below a pinnacle up on the right. Climb over the pinnacle and up the wall on big holds to a ledge on the left. Take the chimney/crack above. The difficulties now ease, but there is plenty more exposed scrambling before the top is reached.

The Hanging Valey

High above Cwm Idwal, contained by the West Face of Y Gribin and the eastern flank of Senior’s Ridge, is the wild and rugged Cwm Cneifion. It is the highest cwm on Glyder Fawr, whose summit is but a short way from its upper reaches.


When seen from the lake shore, the slender spur of Sub-Cneifion Rib stands like a rocky sentinel guarding the entrance to the cwm, and nearly two kilometres further up, the shadowy form of Clogwyn Du commands the headwall. Between them, the two crags offer most of the best climbing in the cwm, but are very different in character.


The Sub-Cneifion Rib is at its best in the afternoon or evening sunlight, and the short pitches of Scimitar Crack Buttress take full advantage of this. Clogwyn Du on the other hand offers more serious fare. Its terrific main face is climbed by several steep routes with exposure to rival the East Buttress of Cloggy.


The summer sun moves off the face early, leaving a more subdued light that adds its own subtle trait to the commitment felt on the routes here. One other line stands out: Cneifion Arête on the West Face of Y Gribin gives a classic ascent from the cwm to the ridge, in the scrambling/mountaineering mould.


The most recent developments in the cwm have been lower down, on the newly-named Craig y Cerddinen, which now boasts one of the modern classics of the Ogwen area. The name Cwm Cneifion derives from the fact that early sheep farmers used to shear out on the mountain. Despite this well-established name, for many years it has also been called the Nameless Cwm, a name which is still printed on the OS map.

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