I never understood why anyone would torture themselves onto a bicycle on such steep hills, tight rural roads and over looooong distances -- call it the marathon of wheels for a yellow t-shirt and "fame" IF you aren't caught doping to win.
Consult this, if you want some superhuman details! Total domination by Merckx, also. Bikes really got better since to cover 4000+/- Kms in a few weeks.
Is the Louvres museum still open when the Champs-Elysées boulevard gets shut down to traffic when the final stretch clocking pushes the last bunch to a photo-finish at the wire?
Never been in Paris.
I had plans, though.