With its height and fluid architecture, the Rotunda Tower has a threefold urban function: – It is first of all a landmark. Installed on the large glass hall of the new station, it asserts the entrance to the station at the level of Place Léon Blum. On the scale of the city, it is a signal. Because of its height, it is visible from several points in the city, and signals that Issy les Moulineaux belongs to the great metropolitan circle. The Rotunda Tower is part of the tradition of the very beautiful Parisian rotunda corner buildings, and also echoes the New York flat-iron.
The specificity of the Rotunda Tower is the variation on the rotunda principle. Not one curve, but two curves of different diameters. Two curved verticals are associated with the nature and different widths of the roads forming the corner: a wide, major tower facing Avenue de Verdun, and a narrower, minor one facing Rue Aristide Briand: a figure that refines the vertical on Place Léon Blum.