Polo also appears as the pivotal character in Italo Calvino's novel Invisible Cities.

Invisible Cities plus Land of Isolation (2011)

Invisible Cities, 2001.

More recently, he has made photographs in post-war Afghanistan (Hidden) and urban Africa (Invisible Cities).

He is involved in a long term project, the Invisible Cities String Quartet Cycle.

Invisible City follows their struggles with academic and behavioral issues, and their sense of futility.

Perhaps you consider it impossible to choose from within a structure as organically perfect as "Invisible Cities"?

Plato's Invisible Cities: Discourse and Power in the "Republic" (1990).

"If On a Winter's Night a Traveler" and "Invisible Cities" are absolutely amazing.

However, the Invisible Cities was her major cycle.