As a general rule, once a city erects turnstiles to tourist attractions which were once free to visit, it is time to go elsewhere. Never more so than in the case of Rome. Last week the Italian capital introduced a €2 charge to visit the Trevi Fountain. Tight-fisted tourists like me will still be able to see the Trevi from a distance – it happens to stand in a public street. The charge will be only for sad Instagrammers who want to get close enough to chuck their coins in the water. The city’s tourism department has suggested the fee...