The St Kilda archipelago lies in the Atlantic Ocean, 45 miles west of the Sound of Harris in the Outer Hebrides. On a clear day, the stacs of the island are visible from there. Over the years this distant vision has proved an irresistible temptation to the would-be explorer. The archipelago consists of four main islands, Hirta, Boreray, Soay and Dun and numerous stacs and skerries, of which the Stac an Armin and the Stac Lee are the highest in Britain, being 191m and 165m respectively.
The landscape of St Kilda was fashioned by volcanic action and the violent action of wind and water. About 60 million years ago, a rift in the northern continent caused widespread volcanic activity. The land between Hirta and Boreray, collapsed inwards and St Kilda’s jagged, eroded cliffs and sea stacs were thrown up. The incredible upheaval which took place has created some of the best cave and tunnel dives in Europe. With almost gin-clear visibility and, what has been described as the finest marine life in Britain, St Kilda is fast becoming a ‘must’ on the list of places to dive.