A fantastic photo from Jean-Luc Raymond on Instagram of an old Metro map that’s just been revealed behind multiple layers of billboard advertising at Les Halles station. Definitely looks like it used to have a street grid layer which has faded away with age.

I’m not entirely sure of the vintage, although I’d say it can’t be from before 1979, as that’s when the RER C opened. It’s the thicker yellow line across the top of the photo with stations at Quai d’Orsay and St. Michel. The map’s typographical treatment – with names for interchange stations set in all caps Futura Bold – would also seem to point to that general era. Any further ideas on dating this?