For over four years in the early 1990s, when I lived near Stirling and travelled to work by train, I walked a short distance through the convulsions of Edinburgh’s Old Town from Waverley Station to a small close off the Canongate. I don’t need to labour the magic of Edinburgh as a city to explore on foot, including as it does a volcano to climb, wheeling gulls and views to the Forth, and a National library housing eight acres of books in storeys climbing between two streets stacked one above the other. In some cities ‘enchantment engineers’ design temporary illusions…