You really feel you have reached the end of the world when you travel to the Hermaness NNR on remote Unst, the furthest north of the Shetland Isles. There’s a good reason for this – you are closer to the Arctic Circle than you are to London, closer to Bergen in Norway than you are to Aberdeen, and at 60º N, on the same latitude as the southern tip of Greenland. Vast colonies of sea birds nest every year on the white guano-stained cliffs and sea stacks, filling the air with their clamorous cries. As well as fulmars and guillemots, gannets glide past, searching the waves relentlessly before diving like feathered arrows into the surging sea. Puffins waddle from their clifftop burrows in early summer and, away from the bustle of the cliffs, dive-bombing great and arctic skuas – locally known as ‘bonxies’ – and red-throated divers nest on the open moorland.