All of Calvino’s works reflect an interest in fantasy and the fantastic. The unusual feature of The Baron in the Trees is that it reflects the supposedly contemporary idea of escape from an oppressive world against the intellectual and political ferment of the late eighteenth century. This was the period of the French philosophes, Deism, which claimed that God created the world but takes no active part in running it, and the American and French Revolutions.

In his later writings, Calvino played variations on fantastic themes drawn from semiology, the study of signs. Le cosmicomiche (1965; Cosmicomics, 1968) considers the relationship of picture and meaning. Le citta invisibili (1972; Invisible Cities, 1974) reimagines Marco Polo—who, in Calvino’s rendering, uses evocative language in the most precise way possible to describe cities which only he has seen to Kubla Khan, the Mongol emperor of China. Il castello dei destini incrociati (1969, 1973; The Castle of Crossed Destinies, 1977) employs speechless tellers of tales who use tarot cards to tell the stories of their lives, and Se una notte d’inverno un viaggiatore (1979; If on a Winter’s Night a Traveler, 1981) presents numerous variations on a single event, a novel read with pages of another work mistakenly bound within it. Calvino’s creative works are often read alongside his countryman Umberto Eco’s essays on semiotics. Eco is himself the author of the semiotic mystery Il nome della rosa (1980; The Name of the Rose, 1983).