The city of Rome is one of the best examples of how urban space is a scenario
of transitions and metamorphosis. This article recognizes the city as an emblem of the
dissent between formal and informal, going beyond the definition of Municipality
and Metropolitan Area. Cities are potentially a legal system in themselves, capable
of producing rules and norms arising from the need for interpretation community
requirements. Informality, therefore, can be found in a whole series of behaviors,
individual and collective, that move from a logic of solidarity, reciprocity, and
gratuitousness. The idea is to show with a case- study how as in the informality
emerges the collective interest to produce benefits, social and economic value for
the entire community. A new interpretation of the dialogue between formality and
informality aspires to be at the center of the debate for a renewed idea of city
