Litterally the one picture I took yesterday, so it has to be this one.
This is a close shot of the switches of a PILI. The "plan indicateur lumineux d'itinéraire" was an interactive map of the Paris Métro; basically, every switch stands for a Métro station, you press the switch for your destination and the shortest path from the station you're in lights up on the map. These were first built in the 1930s and many were still in use less than 10 years ago; as far as I know they are all out of order by now.
As an aside I have never been able to find out how they worked. Of course every path was hand-wired, which made every PILI different. The obvious circuitry would involve a diode matrix, but I'm not sure the diodes they had in the 1930s were small enough to fit in the box.