There are a number of superb boulders to be found in and around the slate quarrying town of Bethesda. The most important ones are arguably the Braichmelyn Boulder and the Caseg Boulder. Both are idyllically situated, the former in a sparsely wooded glade and the latter on the banks of a tranquil stream. Both boulders give excellent, intense climbing on perfect rock. The landings are good too. Stand out problems include the classic Caseg Groove 6C+ and the Braichmelyn Ramp 5C.
The Wave, an escarpment hidden in woodland above Ogwen Bank, is also quite good, but perhaps better is the nearby Tavistock Square face which sits just under the A5 100m along from Ogwen Bank. There are other esoteric wonders, such as the Thumb Boulder above the north end of Gerlan and a high wall in the Afon Caseg Gorge.
The main boulders dry quickly after rain but are also fairly sheltered. Shade can be found at The Wave but this area is slow to dry after rain. This is a fairly low altitude area so year-round bouldering is possible, although it can get a bit midgey on summer evenings.
The approaches are all quite intricate and split off from various points around Bethesda. In some places, particularly Gerlan (the area adjacent to the Caseg Boulder) parking is very limited so it is best to park further down the hill in Bethesda and walk up.