There is always a magic about an island and Eriska is no exception. Nestling on the eastern side of one of the world's most celebrated rift valleys, and born of the cataclysmic upheavals of more than 600 million years ago, the formation of the island is largely of schist and slate with the lower ground to the west as a raised beach from the island. The partly submerged Crannog, or fortified dwelling, dating from the Bronze Age around 200 B.C and situated some 200 metres in the channel to the east of the bridge, marks the earliest recorded human history of the island.