With an estimated population of 120 and a total area of just under three and a half square miles, there’s little on the face of it to suggest the Hebridean island of Iona as a magnet for travellers. Yet for centuries, people have come – first the 12 followers of Columba who landed with him in 563, and later the monks who came to live, work and pray in the monastery he established. In the early 13th century a Benedictine abbey was raised on the spot of the original building and today the site and the island are revered as the central point for the spread of Christianity throughout Scotland, and accepted as one of the oldest religious centres in western Europe.

The faithful still travel to the abbey and they’re joined by enthusiasts for history both medieval and modern – 60 Scottish kings are buried on the island, but so too is John Smith, a former leader of the Labour Party who died in 1994 – and of course their number is swelled by those who would simply describe themselves as tourists.

They, like everybody else, arrive by boat, hopping onto the CalMac ferry at Fionnphort on the Isle of Mull for the short 10 minute crossing to Baile Mòr, the small settlement which passes for Iona’s capital. The best way to go is on foot, the way pilgrims have always travelled. The Abbey itself is only a short walk away and there are good beaches on the other side of the island and hard by the ferry landing place. There’s also a campsite, two hotels and a sprinkling of B&Bs, and of course the Abbey still hosts a great many who simply want to make a retreat.

Even the casual visitor can sample the same sense of peace that Christian visitors seek. Your correspondent has visited twice and on each occasion been treated to a vivid rainbow on the crossing – proof, perhaps, of the truth behind George MacLeod’s famous claim that Iona is “a thin place, where the veil between things spiritual and things material is as thin as gossamer”. A high-born Scot who saw action at Ypres and Passchendaele in the First World War and was decorated for his trouble, it was MacLeod who in 1938 founded the Iona Community, a forward-thinking Christian community headquartered in Glasgow.

Once visited, never forgotten is a trite and over-used phrase. Where Iona is concerned, it’s entirely true.