All cities have their secrets, and Paris is no exception. It has its secret places too, but these are not deep underground or hidden behind high walls. The best way to hide a building in a city it seems is to make it as banal as possible.
A police presence needs to be visible in a city, but what about the back end of the operation? Where do they stock equipment, make repairs, test new products and programme support software? The answer in Paris is at the Direction Opérationnelle des Services Techniques et Logistiques, and an obscure building in the 13th arrondissement.
What occurs inside exactly is not entirely clear. Indeed, it's not entirely clear exactly how you get inside! The official address is 4 Rue Jules Breton, but there does not even seem to be a door at this address (apart from a rather large garage door). Walking around the perimeter of the building (either on foot, or virtually via Google maps) makes the access problem no clearer (although via Google you do get a sneaky view into a garage where several marked and unmarked police cars are parked). This is a structure closed to outsiders, with no mention of its purpose, and only a pair of French flags and a couple of security cameras show you that this is an official building.
So what does happen inside? A recruitment site gives a vague idea. This is a place where the police get their uniform and guns, where vehicles and communication tools are tested and repaired, but also a place where heavy machinery (helicopters, boats) can be supplied. Clearly it has a role to play in surveillance too, possibly from the rooftop rooms which must also offer fantastic views across the city.
The insides of this building are destined to remain a mystery, but perhaps its better that way. We can imagine an Ali Baba's cave of technology, staffed by slightly eccentric Q clones, but the reality is probably a lot more ordinary. The outsides - cracked and grimy concrete - already seem to tell us that there is nothing to see here.