Rocktype Volcanic tuff
Altitude 230m a.s.l
All the boulders and walls described in the Fachwen section of North Wales Bouldering. The most popular sector is Y Clegyr (not to be confused with Clegir on the other side of Llyn Padarn), but there are many other gems scattered around.
This section of the guidebook is not comprehensive, and many more esoteric and minor problems can also be found here.