The Llech Ddu Spur is an easy but exhilarating scramble that leads directly from the Cwmglas Bach hanging cwm to the summit of Carnedd Dafydd. From the spur you will enjoy (weather permitting) amazing views of the secluded Cwm Llafar valley and of the neighboring Carnedd Llewelyn and Yr Elen.
This climb is best accessed from Bethesda. Bethesda is directly accessible from the A5. If driving park anywhere you can find a spot in Bethesda as it is a rather small town.
Once in Bethesda walk towards the old waterworks. Once at the waterworks cross though three stiles and enter the Cym Llafar valley. Hike along the right handside of this spectacular valley until your reach the end. Carnedd Llewelyn is at the head of the valley and Carnedd Dafydd on the right. You should see a waterfall leading down into the valley from a hanging cwm (Cwmglas Bach).
The spur is gained by climbing up into the hanging cwm. Once you are in the Cwmglas Bach look for a ramp of mixed grass and rock that that heads left. This will lead you onto the base of the spur. Begin scrambling upwards over broken ledges as the spur narrows. Continue following the crest to gain the broad boulder strewn summit. If the weather is foggy be careful as there are a few dropoffs near the summit. The summit is marked by a large cairn so a little bit of wandering should get you there even in nasty weather.
The traditional descent would be to traverse to Carnedd Llewelyn to complete the Cwm Llafar horsehoe. From the summit follow the path along the ridge to gain the summit of Carnedd Llewelyn and then complete the horshoe by following the obvious path to the summit of Yr Elen. Descend Yr Elen slightly then head back down into the Cym Llafar. Look for a likely spot to cross the river that runs through the valley to gain your starting point.
No climbing gear is needed other than a pair of trusty boots.