Urban areas represent complex systems whose transformations are taking place with different forms, ways and times in several international contexts. The volume collects theoretical, methodological and researching contributions representative of the contemporary debate on public space both as an ordering element of urban phenomena and as an environmental infrastructure. The public space of European cities is a significant social condenser which is the bearer of multiple dimensions: a resting and crossing space in which flows of people, goods and information; a place of singularity and excellence or abandonment and degradation.