When a company like Cartier celebrates being on Fifth Avenue for 100 years, expect nothing short of over-the-top fabulousness. To kick off the festivities, the house hosted a star-studded party (Demi Moore, Justin Timberlake, and Kate Hudson were in attendance). But for the entire month of May, Cartier is showcasing 100 pieces belonging to some of the most recognizable names in American and European history. It's not every day the public can see a free, museum-worthy jewelry bonanza. But if trekking through the touristy-throngs on Fifth isn't in the cards, here's a glimpse of some of the stunners on exhibit and the rich people who owned them.