Snowdon, Grib Goch, Glyder Fawr, Y Garn & Elidir Fawr from Llanberis Trail Running Route
Crib Goch is one of the most exposed ridges in Britain, and this route puts it in the middle of a big mountain day rather than as the whole objective, so you get the scramble and a proper crossing into the Glyderau either side of it.
Effort: Ultra distance and major ascent
Underfoot: Exposed, scrambling or very rough
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A real mix of running and walking — expect significant climbing.
A 30km mountain round from Llanberis over Snowdon's summit and the exposed knife-edge of Crib Goch, pushing on into the Glyderau before returning. 2,204m of climbing on serious, exposed ground.
Crib Goch is one of the most exposed ridges in Britain, and this route puts it in the middle of a big mountain day rather than as the whole objective, so you get the scramble and a proper crossing into the Glyderau either side of it.
The route
From Llanberis, this climbs to Snowdon's summit at 1,085m before dropping onto Crib Goch, the narrow, exposed ridge that's become one of the most talked-about scrambles in Britain. The GPX confirms the track crosses right along the ridge rather than skirting beneath it, so this is a route that commits you to real exposure rather than just admiring it from below. From there the line continues east toward the Glyderau, adding distance and climbing beyond the Snowdon massif itself before the return.
Crib Goch
There's no way to undersell Crib Goch: it's a narrow rock ridge with drops of hundreds of metres on both sides, rated a grade 1 scramble but treated by most people who've done it as considerably more serious than that grading suggests. It should only be attempted in dry, calm conditions - wind and wet rock turn it from a serious proposition into a genuinely dangerous one, and several people die on this ridge most years. A helmet is worth carrying given the risk of dislodged rock from parties above.
Into the Glyderau
Beyond Crib Goch the route continues toward the Glyderau, Snowdonia's other great mountain group, adding real distance and height gain to what's already a full day. This is where the 2,204m of climbing comes from - not from a single big pull, but from a long, high traverse that keeps you on serious ground for hours rather than minutes.
Getting it right
This is not a route for a first visit to the mountains. It needs a settled forecast, proper navigation skills for when cloud sits on the ridge, and the fitness to keep making good decisions many hours and several summits into the day. Done in the right conditions it's one of the best mountain days in Wales; done in the wrong ones it's genuinely one of the most dangerous.
Crib Goch is a grade 1 scramble with severe exposure on both sides and should only be attempted in dry, low-wind conditions - it is not survivable to fall from. Cloud and wind on the ridge make retreat as dangerous as continuing, and the long push into the Glyderau leaves little margin if the weather turns.
Summits on this route
Safety on this route
- No signal? Text 999 — pre-register first: text register to 999
- Tell someone your route and expected return time before you head out
Leave No Trace
- Leave nothing but footprints, take nothing but memories.
- Please respect the countryside and all its inhabitants.
- Dogs on leads near livestock, and around ground-nesting birds from March to July.
- Gates as you find them — open or closed, leave it that way for the farmer and the next runner.
- Take it all home — wrappers, peel, tissue, the lot. It doesn't count as biodegradable if you can still see it.
- Stick to the path where the ground either side is wet, planted, or nesting habitat.
Common questions
Run by us· last checked July 2026
Jason Millward has run this route and written it up from the ground. How we check routes
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Runner reports
Nobody's logged a run here yet. If you get out on it, a few lines about how it went helps the next person plan their day.
