501 Must-Visit Cities (the book by D. Brown) is an invaluable source of inspiration for those seeking to explore the great cities of the world, either in reality or from the comfort of an armchair!
Here you will find the world's largest and most dynamic cities, such as Mexico City, Tokyo, Mumbai and New York, alongside many cities which are on a very different scale altogether: St David's in Wales (with a population of only 1,600 it seems more of a village than a city), Bulgaria's 'Pearl of the Black Sea or Colonia del Sacramento, Uruguay's oldest city.
