Paris Métro entrances by Hector Guimard

[2][3] Adrien Bénard, the financier whose bank was underwriting the construction, liked the new Art Nouveau style and therefore instead persuaded the Compagnie du chemin de fer métropolitain de Paris (CMP) to appoint the still young Hector Guimard to design the entrances to the underground stations,[4][5] while the elevated stations were designed by Jean-Camille Formigé, chief architect of the City of Paris.

[6] Rather than stone, Guimard used cast iron set in concrete both to reduce costs and to suit the sinuous Art Nouveau forms;[3][6] they were painted in a green emulating weathered brass.

[6][10] Three of the entrances took the form of free-standing pavilions or small stations,[5] including waiting rooms: one at Bastille and two on Avenue de Wagram at Étoile.

[15][16][17] These were not ready until 1901, the year after the system first opened, and Guimard varied the "Métropolitain" lettering somewhat between stations and twice revised the design, which reached its final form in 1902.

[21] On the Champs-Élysées, for example at Marbeuf (now part of Franklin D. Roosevelt), simple stone walls with discreet carved signage were used instead,[10] and a plain design was also used at Bourse.

[22][23] Unhappiness with Guimard's 1904 design for the Opéra station,[24] described in Le Figaro as having "contorted ramps" and "enormous frog-eye lamps",[25] and increasing costs led to the CMP severing its relationship with him.

[20] The CMP continued in later years to replace some of Guimard's designs with more sober entrances by Cassien-Bernard, often a plain balustrade in white stone, for example at Gare de l'Est, Madeleine, Montparnasse, and Saint-François-Xavier.

Some subway systems and museums outside France have examples of Guimard Métro entrances, mostly replicas presented by the RATP in exchange for art works.