This symposium is part of a series of Franco-Brazilians that started in 2016 entitled "Imaginary: Building and Inhabiting the Earth". Its aims this time is to continue and deepen the questioning of the three previous editions, but within an urban context. It also deal with the inhabited world's imaginaires through the prism of the transitions, issues, dynamics and paradigms of the 21st century. This will come down to characterizing what these immaterial and material forms, here called imaginaires, are;  identifying what these same imaginaires forms are producing as ways of feeling our urban environment and how imagination is framing, guiding and making this experience possible; analysing what the register of the imaginaire is producing as anchors, aspirations, projections or utopias for individuals, groups and societies; finally identifying how individual and collective practices are producing new imaginaires forms and/or enrich existing ones