Their function is clear: to mark and protect the underground entrances while blending harmoniously into the urban landscape.
It’s worth noting that, while today these structures made of iron, cast iron, and glass, which shelter the staircases while allowing natural light to filter through, are among the most recognizable and beloved symbols of Paris, this was not always the case. Deemed too fanciful upon their installation, they fell completely out of fashion when the Art Nouveau style gave way to Art Deco in the 1920s. Gradually replaced by more sober and austere stone or concrete entrances, they were fortunately saved from total destruction thanks to André Malraux (Minister of Culture under General de Gaulle), who designated the last remaining ones as Historic Monuments in 1965.
Protected and restored, they then became icons of Paris and, in a sweet act of revenge, sometimes even regained their original locations thanks to exact replicas that Hector Guimard would certainly have approved of.