Italo Calvino's Architecture of Lightness: The Utopian Imagination in an Age of Crisis by Letizia Modena, published by Routledge , 2011. Hardcover, 284 pages. ( Amazon ) Like many architects, I first encountered Italo Calvino's 1972 book Invisible Cities in undergraduate architecture school. Not surprisingly, it was assigned reading for a semester spent in Italy, alongside titles like Aldo Rossi's A Scientific Autobiography that can be said to be more architecturally relevant. Calvino's book is a fictional discussion between emperor Kubla Khan and Venetian traveler Marco Polo, in which the latter describes 55 cities that he has apparently visited within the former's domain. The cities -- falling into categories like "cities and memory", "thin cities", and "hidden cities" -- are highly fantastical, defying logic, sometimes gravity, and the "rules" that determined traditional cities. One conclusion determines...