Calvino gives each of the 55 cities Polo travels to women’s names and classifies them under 11 themes, such as “Cities and Memory,” “Cities and Desire,” and “Cities and Signs.” He gives each return to the theme an advancing number, never exceeding the value of five. These returns to the same theme are also mathematically determined, as he often leaves a regular or mathematically sequenced gap between cities under the same theme.

The mathematical coherence of these thematic patterns creates an alternative view of the narrative, as Polo organizes his experience in a different manner from the way he narrates it to Khan. A coherent journey or train of philosophical thought can be viewed across a theme. For example, in “Cities and Memory,” Polo ponders the difference between one’s experience of a city and their expectations or memory of it. By Maurilia, the fifth city under this category, Polo concludes that the experienced, remembered, and expected cities are all different places rather than the same one. Themes are concluded and replaced by new ones during the scope of the text. Some of the themes, like “Cities and Signs” and “Cities and Names,” which explore how far cities can be defined in human symbols, have similar preoccupations.