All great cities have one thing in common: once you have visited their renowned monuments, museums and historic sites, there remains much to explore.  And so it goes with Paris.

After you have seen every room in the Louvre and every impressionist masterpiece in the Musée d’Orsay, there is still le Centre Pompidou, l’Orangerie, le Musée Rodin, le Musée Picasso — and these are the well-known museums.

There are plenty of unknown museums, too, places that even some Parisians haven’t heard of or visited. These overlooked cultural institutions are never crowded, even on Saturday afternoons, and on weekday afternoons they can be downright deserted.  I love that.

The photo above was taken at le Musée des Arts et Métiers at the end of a weekday afternoon and, as you can see, I nearly had Clément Adler’s bat-inspired flying machine ”Avion III” to myself.  L’avion is one of the museum’s gems, along with a copy of Foucault’s pendulum, which hangs in the adjacent Saint-Martin-des-Champs church.