Cwm Idwal comprises volcanic and sedimentary rock which was laid down in a shallow Ordovician sea, and later folded to give rise to the distinctive trough-shaped arrangement of strata known today as the Idwal Syncline.
Cwm Idwal is composed of volcanic and sedimentary rock that was deposited in a shallow Ordovician sea, and later folded to create the distinctive trough-shaped arrangement of strata known as the Idwal Syncline.