St Columba arrived in 563 AD. He had grown up in Ireland, become a monk, and then quarrelled badly enough with the established church there to be exiled. Tradition says he sailed first to Kintyre, took one look back across the channel, saw Ireland still on the horizon, and concluded he was not far enough away. He kept sailing. Iona was finally past the curve of the earth from his enemies. He founded a monastery here with twelve companions, and within a century it had become the spiritual hub of a network of churches across western Scotland and Northumbria. The original Iona Chronicle, foundational source for early Irish annals, was probably written here. The Book of Kells, one of the most celebrated illuminated manuscripts in existence, may have been begun on Iona before being moved to Ireland to escape Viking raids in the late eighth century. The monastery fell derelict after the Reformation. The Iona Cathedral Trust began restoration in 1899. Most of the island now belongs to the National Trust for Scotland, the abbey to Historic Environment Scotland.

There were once 360 carved stone crosses on Iona, free-standing or as grave markers. The Reformation broke nearly all of them. Three and a fragment remain: St Martin's Cross still standing outside the abbey church, a replica of St John's beside it with the original in the museum, fragments of St Matthew's, and MacLean's Cross from the fifteenth century 250 yards south. The graveyard Reilig Òdhrain holds the bones of early Scottish kings. The figure quoted is 48, which scholars now think was inflated centuries later to flatter the abbey's prestige. None of the royal plots can be identified today. A modern extension to the graveyard, jutting north, holds the grave of John Smith, the Labour Party leader who died in 1994 and loved this island. Oran himself, who came from Tipperary with Columba, has the strangest legend on Iona. He died, was buried in the foundation of his chapel, and then started popping out of his grave with views the other monks disliked enough to bury him again.

Walk north past the abbey to the top of the island where white sand and clear water open onto views across to Tiree, Coll, Staffa, the Treshnish Isles, Eigg, Muck, and on a good day Skye. Walk southwest to Camas Cuil an t-Saimh, the Bay at the Back of the Ocean, where the surf comes in from open Atlantic and a spouting cave at the south end of the bay throws water in heavy weather. The marble quarry on the southeast coast worked a 7-metre seam of green-streaked stone from medieval times until 1918. Whatever remains of the machinery and the granite blocks that sandwiched the marble vein sits where it was abandoned. Further west the marble gives way to Lewisian gneiss, two billion years old, in cold hues of pink, white, red, green and black. No mobile signal reaches Iona from any UK carrier. There is no ATM. Cars are not permitted to non-residents. Walking, ten minutes from pier to abbey, is the answer to most questions of getting around.