This mural painted by Keith Haring was done without payment as a gift to entertain the children at the Hôpital Necker.

The storefront of a ramshackle Parisian puppet theater.

The approximate spot where the last Grand Master of the Knights Templar was put to death.

What looks like a normal building is really a hollow facade hiding a subway vent.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

The narrowest street in Paris.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

Private collection of art inspired by cabinets of curiosity.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.