Invisible Cities is a novel by the Italian author Italo Calvino that tells the story of a bored emperor, Kublai Khan, who asks the newly arrived Marco Polo to travel his kingdom and bring back tales of his what he sees and finds.

As the author states:

Kublai Khan does not necessarily believe everything Marco Polo says when he describes the cities visited on his expeditions, but the emperor of the Tartars does continue listening to the young Venetian with greater attention and curiosity than he shows any other messenger or explorer of his.

Polo divides the cities into the following categories: Cities of memory, cities and desire, cities and signs, thin cities, trading cities, cities and eyes, cities and names, cities and the dead, cities and the skies, continuous cities and hidden cities. He gives each city a woman's name. As an example the cities of desire includes cities with the names of Desire, Dorothea, Anastasia, Despina, Fedora and Zobeide.

Overall Marco Polo travels or claims to travel to 55 cities, which he describes to Khan in the form of a short prose poem. For example, he describes Dorothea in the following manner;

There are two ways of describing the city of Dorothea: you can say that four aluminium towers rise from its walls flanking seven gates with spring operated drawbridges that span the moat whose waters feeds four green canals which cross the city, diving it into nine quarters, each with three hundred houses and seven hundred chimneys . . . Or else you can say, like the camel driver who took me there: "I arrived here in my first youth, one morning, many people were hurrying along the streets toward the market, the women had fine teeth and looked you in the eye."

As Polo continues talking to Khan in Khan's garden, his descriptions get increasingly surreal and outlandish. For example, he describes Andria as,

built so artfully that its every street follows a planet's orbit, and the buildings and places of community life repeat the order of the constellations and the position of the most luminous stars, Antares, Alpheratz, Capricorn, the Cepheids.

The novel ends with Khan bemoaning the fact that he seems to live in the city of the inferno. However, as Polo states:

The inferno of the living is not something that will be; if there is one, it is what is already here, the inferno where we live every day, that we form by being together. There are two ways to escape suffering it. The first is easy for many: accept the inferno and become such a part of it that you can no longer see it. The second is risky and demands constant vigilance and apprehension: seek and learn to recognise who and what, in the midst of the inferno, are not inferno, then make them endure, give them space.

If Polo's stories aren't true then the reader can only presume they are metaphors to help Khan live a better life.