Paris is the capital of fine jewelry, but it can be an exclusive and secretive world. The private tour company Bijoux Society offers a chance to peek inside. Graduate gemologist Alexis Vourvoulis offers an in-depth tour of the jewelry collection at the Musée des Arts Decoratifs. One of the most comprehensive collections of French jewelry ever assembled, there are gems from the Middle Ages all the way to present day, including famous pieces by Lalique, Belperone, and JAR. Vourvoulis can also serve as your personal shopper in Paris helping people purchase engagement rings and special finds at the Marché aux Puces de Saint-Ouen, like a strand of vintage Chanel pearls or a Schiaparelli cocktail ring. For avid collectors, Vourvoulis may be able to arrange historic archive and private museum visits of some of the famed jewelers on Place Vendôme. Tours from $250; contact firstname.lastname@example.org.