Five thousand years ago this northerly huddle of more than 70 low-lying islands was one of Europe’s most important religious centres, but today the Orkneys are a sleepy outcrop of the United Kingdom; the flat, green landscape devoted to farming, tourism and twitching. The largest town on the largest island (called, imaginatively, Mainland) is Kirkwall, and it is such a cosmopolitan place that one of the first things I saw was a sign warning: ‘Watch out, otters crossing.’