The Métropole du Grand Paris, or simply Grand Paris, formally came into existence on 1 January 2016. It is an administrative structure for co-operation between the City of Paris and its nearest suburbs. It includes the City of Paris, plus the communes of the three departments of the inner suburbs (Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne), plus seven communes in the outer suburbs, including Argenteuil in Val d'Oise and Paray-Vieille-Poste in Essonne, which were added to include the major airports of Paris. The Metropole covers  and has a population of 6.945 million persons.