This paper deals with the confrontation between the forms of urbanisation of Lisbon, Portugal, that extends its fringes over the Alcântara Valley. This same Valley—topography and hydrography—plays as determinants of the occupation that will assume distinct narratives. This gradual process is explained through three narratives about (1) the urbanisation of the margin driven by industrialisation and the construction of a stigmatised periphery, (2) the imposition of large capacity infrastructures far beyond what is local, (3) the system of open spaces and landscape projects and the urban brink that the valley claims. The debate focuses on the answers that the urban and landscape project, necessarily going through urban planning and its practical and theoretical scopes, i.e., Urbanism and urban planning thinking, especially in a broad present seeking to discuss both sides of the coin: on the one hand, an urban rehabilitation with public space for all, on the other hand, a qualified and central space that attracts real estate investment that may bring effects contrary to those expected. The article seeks to contribute (1) to a broader perception of the superimposition of processes that transformed the Alcântara Valley, (2) to a fuller dissemination of the urbanistic experiences in the city of Lisbon since this city is still vastly underrepresented in the international (primarily Anglo-Saxon) literature, (3) to deepen the debate between urban rehabilitation, urban regeneration, consequences and opportunities practiced is still trying to cope with.