Garreg yr Ogof | ©Si Panton



The superb Garreg yr Ogof, situated on the shores of Llyn Trawsfynydd is a gem, well worth seeking out. This sunny, gritstone micro crag can be reached quickly from the nearby village of Trawsfynydd. Most visitors come to try Bloodscream 6C - a classic arete on the upper edge, but there is a wide range of excellent low and mid grade problems to be enjoyed too. Be sure to check out the Undercut Wall closer to the lake where you will find lines up to 7A.

The rock is more blocky and edgey than Pennine grit, but the frictional qualities are just as fine. The landings are mostly good and the aspect, aside from the power station to the north, is delightful. The Rhinogydd hills across on the west side of the lake offer much potential for exploration and ‘adventure bouldering’ – just go prepared for some long walk ins and some rough terrain.


This is a quick drying venue blessed with more than its fair share of sunshine. Year round climbing is possible, in fact a sunny winter afternoon here is a real treat.


From the centre of Trawsfynydd, near the church, follow a public footpath around some houses and out across a small field towards the lake. When you cross the final stile you will see a rolling grassy area leading down to the lakeside. Bear slightly left to reach the upper tier. Other smaller escarpments lie closer to the water’s edge.

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Safety & Access

The publisher of this website accepts no responsibility for the way in which readers use the information contained therein. The descriptions and recommendations are for guidance only and must be subject to discriminating judgement by the reader. Advice and training should be sought before utilising any equipment or techniques mentioned within the text or shown in any of the photographic images. Bouldering is an activity with a danger of personal injury or death. Participants in this activity should be aware of and accept these risks and be responsible for their own actions and involvement.


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