St Gwynhoedl evangelised in the Lleyn peninsula having his church at Llangwynnadl on the north side where a huge pilgrim church arose. His bell is in the National Museum at Cardiff though a replica remains. He is buried at Llanbedrog, founded by St Pedrog (6C), where there is a tombstone of the saint. But(!) the church at Llangwnnadl also has a grave slab hidden since the 6th century and which was rediscovered in 1940.
