In Île-de-France 39 employment hubs bring together 43 % of people in work. Among them ten or so are located in the centre of the Parisian conurbation and concentrate three-quarters of all these areas of dense employment.
In Paris the central business district is by far the main hub of the Region, followed by its extension to the west, namely at the Défense as well as by other major centres within the city of Paris proper.
In the inner and outer suburbs, there are approximately thirty hubs of varying sizes, some of which specialize in certain domains.