The territory is a "construct" through political action and the experience of its residents. In order to influence its future it is necessary to identify the concerned stakeholders as well as to bring together different perceptions regarding the territory. Politicians act on the territory through projects. These projects can have as main purpose a new space of governance, new limits or new structures. Moreover, they can also be based on themes shared by the stakeholders and capable to mobilize them and bring them together. Regarding the Estuary of the Seine, a process of territorial construction has been started by the politicians with the opening of the Pont de Normandie (Normandy Bridge). The thematic project of tourism and leisure development in the Estuary is part of this sequence and builds on the new territorial concept resulting from the political decision making process. Implemented by experts, the project targets strategic issues regarding identity, economics and diplomacy. Realized within the Agence d'Urbanisme de la Région du Havre et de l'Estuaire de la Seine (Urbanism Agency of the Region of the Le Havre and the Seine Estuary), this thesis aims to demonstrate how a thematic project, in this case concerning tourism and leisure, contributes to the success of a political territorial project, in line with the concerned citizens.
