André Masson's first, and perhaps greatest, contribution to the Surrealist movement was the creation of automatic drawing in the '20s, a plastic transcription of André Breton's automatic writing: a spontaneous drawing style characterized by free gestures. Nevertheless, from the late 1930s onwards, Masson adopted a more controlled, figurative style in subjects often inspired by mythology.

"Ville crânienne", part of the artist's Cranial Cities series, is an example of the second phase of Masson's surrealism. In this striking image, the artist compares the human head to an imaginary city whose complex architecture evokes that of a labyrinth, a visual metaphor for the subconscious.