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
Anglesey near the north coast. There are plans for the world's first Tidal Flow turbines, near The Skerries, off the north coast, and for a major biomass plant on Holy Island (Ynys Gybi). Developing such low-carbon energy assets to their full potential forms part of the Anglesey Energy Island project. When the aluminium smelting operation closed in September 2009, it reduced its workforce from 450 to 80; this has been a major blow to the island's economy, especially to Holyhead. The Royal Air Force station RAF Valley (Y Fali) is home to the RAF Fast Jet Training School and also 22