Holy Island, Anglesey Rhoscolyn, and Four Mile Bridge. Around of the Anglesey Coastal Path is on Holy Island. Peripheral islands and stacks include North Stack, and South Stack, with its famous lighthouse. Before – and even after – the construction of lighthouses, the cliffs and jagged rocks of the island were a great danger to sailors. Holy Island, Anglesey Holy Island (, 'the island of (Saint) Cybi') is an island () on the western side of the larger Isle of Anglesey, Wales, from which it is separated by a narrow, winding channel. It is called "Holy" because of the high concentration of standing
Ramsey Island fourth largest island in Wales, after Anglesey, Holy Island and Skomer. The island has a diverse geology for a relatively small area; it comprises sedimentary, volcanic and intrusive igneous rocks dating from the early Palaeozoic Era. The larger part of the north of the island is formed from mudstones of the Tetragraptus Mudstone Formation (also known as the 'Penmaen Dewi Shale Formation' and again as the 'Road Uchaf Formation' (sic) after the Rhod Uchaf locality on the island's east coast). However Carnysgubor stands proud to their west as it is formed from a more resistant microtonalite intrusion. In contrast the