Ifor sets out to understand the appeal of islands as holy retreats. It may seem obvious that we would feel closer to the divine when surrounded by the stunning natural beauty of an island, but Ifor soon discovers there is a far deeper reason they became such a major aspect of religion.

His journey takes him from the Lake District to the Mappa Mundi in Hereford Cathedral, from our most famous holy island at Lindisfarne to the Western Isles in Scotland where an ancient Christian holy island has been reborn as a Buddhist monastery. He visits the island where the Welsh version of St Valentine lived and finally heads out west to the barren island of Bardsey, at the very furthest tip of Wales. This is known as the Island of 20,000 Saints, a place that exists halfway between this world and the next.