GeoGraph - photograph every grid square

Pre-Cambrian Anglesey comprises a number of slices of ancient crustal rocks which have been brought together by tectonic forces. Edward Greenly named them after the places where they were best developed. The Penmynydd Zone is named after the village astride the low ridge of schistose rocks that runs across southern Anglesey. The steep ascent of the road near here is due to the climb across the fault which separates this slice from its neighbour to the North.