Onwards, relentless, through the backstreets we walk to Sultan Ahmet Square is the spiritual hub of İstanbul, and in the l970s was the place to be. At the Pudding Shop on the north side of the square, dazed hippies returning from the East sold beaten-up VW vans to pale young students about to embark on the overland trail. Today the Pudding Shop is a clean, ordinary self-service restaurant.