St Magnus Bay

St Magnus Bay is a large coastal feature in the north-west of Mainland Shetland, Scotland. Roughly circular in shape with a diameter of about 19 kilometres (12 mi), it is open to the North Atlantic Ocean to the west. The indented coastline to the north, south and east between Esha Ness in the north and the Ness of Melby in the south contains numerous bays, firths and voes and there are several islands around the perimeter. The waters of the bay are up to 165 metres (541 ft) deep and may have been the site of a substantial meteor impact.

The geology of the area is complex and there are numerous caves and cliffs around the coastline, which has been inhabited since prehistoric times. The sheltered inner waters of the bay have provided a refuge for vessels in times of both peace and war. Shetland was part of the Scandinavian world from the late first millennium until 1469, when the islands became transferred to Scotland and as a result most of the place names around the bay and some of its present-day culture are of Norse origin.