"We discuss the opportunities of participation of adolescents living in peripheral districts in terms of planning and management of urban spaces. Our concern in studying the urban space is related to the fact that 80% of the world population lives in cities (Pol, 2000), what is causing a series of critical social and environmental problems, which are a spatial materialisation of the predatory model of development typical of the modern industrial societies. The sustainability of urban centres is threatened by the physical interference of human occupation and by the scale of the social-environmental impact caused by these human agglomerations. The spatial scale is also important for the construction of a place identity, because a physical and affective distance between person and environment compromises the process of appropriation of that space. Thus, the district, the "local community", seems to offer the best opportunities for the development of experiences of popular participation (Pinto, 1989)."