The Emperor’s Gold: Treasures of the Banque de France

To penetrate into the inner sanctum, you must first show your credentials, exchange your ID for a badge, pass through an armored security gate, walk through wide corridors and descend deep into the building’s bowels until at last reaching a mysterious red double door. Once the ornate, artistic covers concealing the lock are located, the yellow and black keys, each held by a different person, are turned; the lock clicks. Heavy, 1,850-kilogram steel doors swing open into a huge, empty, dimly lit room: the secret place where the Banque de France houses its treasures . The few visitors come face to face with a monumental clock—perhaps to recall that, as Benjamin Franklin said, "time is money"—a scale for weighing bags and two deep coin scoops. For a long time, this underground chamber designed by architect Alphonse Defrasse in the 1930s was a place where wealthy customers stashed their securities. Ten years ago, it was turned into a museum that very few people know about. An even row of wall cabinets divided into small compartments house rare objects. Arnaud Manas, head of the heritage and archives department, takes out a velvet tray of Napoleon's personal medals from one of them.…