Like Ystradfellte, the pavement is on a very pure limestone with less than five per cent insoluble residue. Local rumour has it that a stunning circular formation of clints was the result of a World War Two bomb, but in fact it is a natural feature formed by water running to a central point, gradually dissolving the limestone in its path. Eyarth Rocks in North Wales may be more difficult to find than the Great Orme. However, the main pavement is an excellent expanse of clints and deep grikes which hold a good associated woodland flora. This includes yellow archangel, which is unusual for British pavement sites.
Limestone pavements hold great interest for biodiversity.
Their clints and grikes create microclimates allowing ancient woodland species like lily of the valley and herb robert to survive, despite being surrounded by miles of grazed moor and grassland.