In the novel Invisible cities (1972), Italo Calvino relates an imaginary meeting between the aged Kublai Khan and the young Marco Polo. The latter tells of the many cities he has visited: trading cities, thin cities, continuous cities, hidden cities, cities and memories, cities and desire … After more than fifty stories, the Tartar emperor begins to realize that all the cities Marco Polo describes in fact represent different aspects of the storyteller’s home town, Venice. This sense of diversity may well be one of the keys to successful urban cultural policies for the new millennium.