The "Bassin Parisien". A tour through the tradition of research and action of the Datar - The "Bassin Parisien" is an interpretative and project related image that is particularly laden with meaning and history and which for some time now has formed part of the aménagement du territoire in France and in Île-de-France. Indeed, in so far as it straddles the fields of research, politics, economic development and planning, it in part represents aménagement. Put forward in the 1960s by the Datar (Délégation à l’Aménagement du Territoire et à l’Action Régionale), aménagement is today the subject matter of fresh contemplation by the refounded Datar, which has just launched a new series of studies and research projects targeted at understanding its actuality and operativeness in the wake of the challenges of the contemporary city. Project manager Eliane Dutarte traces its history and illustrates its potential. Key words: aménagement du territoire; Bassin Parisien; Datar.