Why do people go on pilgrimage to Iona?

Iona is a small island off the western coast of Scotland. It was a centre of Irish monasticism for four centuries. Christians go there as a place of Christian retreat, and to share in the onetime place of residence of the famous Columba (521-597).

Columba was exiled to Scotland because of a dispute in Ireland in which he was involved that resulted in a number of deaths.

His move to Iona was a turning point in his life, since Columba is credited with evangelising the Picts of Scotland, and turning the island into a school for missionaries.