The St Kilda archipelago, the remotest part of the British Isles, lies 41 miles (66km) west of Benbecula in Scotland’s Outer Hebrides.

The archipelago consists of the main island of Hirta, along with Boreray, Dun and Soay, and the sea stacks Levenish, Stac an Armin (191m) and Stac Lee (165m) – the highest in Britain.

With their exceptional cliffs and sea stacks, the islands form the most important seabird breeding station in north-west Europe. The world’s largest colony of gannets nests on Boreray and the sea stacks.

St Kilda is one of the best places in Britain for diving because of its clear water and its submerged caves, tunnels and arches.