Invisible Cities is a collection of 55 short prose poems about fictitious cities, embedded in a conversation between Marco Polo and the aging Mongol ruler Kublai Khan, Founder of the Yuan Dynasty and thus emperor of China: Having conquered vast amounts of territories, the emperor feels a sense of emptiness, as he realizes he will not be able to know or understand all parts of his empire. Therefore, he employs Marco Polo, the famous Venetian traveler, to tell him stories about the cities he has visited during his inspection trips through the extensive empire. Even though diplomats, merchants and other travelers report the situation in his realm, he prefers listening to Marco Polo, as his stories follow a pattern.
Moreover, the two engage in philosophical conversations about language and reality, at some point wondering if everything in the world, including themselves, is just a construct of their minds.
Each of the 55 fictitious cities outlined in a few words illustrates a particular geographical, historical, social or general human situation in a poetic image. Furthermore, each city has a woman's name; however, the emperor soon discovers that Marco Polo uses the same pattern to describe the cities, so he tries to create a description of a city of his own and compares the growth of cities to a game of chess, which follows a set of rules. Marco Polo indeed admits that he has been describing only different parts of Venice, to preserve his memory of the city, which he fears will soon cease to exist as he knows it.
At first, Marco Polo's images seem like a delicate, pastel painting with words, but gradually they become darker and soon create a nightmarish panorama of decay and ruins which resembles our modern world. Thus, Kublai Khan asks if all our efforts are in vain if arriving in the infernal city is inevitable. Polo replies that there are two ways to escape: Either accept one's fate and become a part of the inferno, or look for things that are not inferno and make them endure.
