St. Tro... What?

So here's Bar Refaeli vacationing in St. Tropez which seems to have amazing beaches. That's all I really knew about it until about five minutes ago. And also that a lot of rich people go there. Which is exactly the first sentence describing the place in Wikipedia: Saint-Tropez is a commune of the Var département in southern France, located on the French Riviera. Known for its famous and wealthy guests, it is often called the Marbella of France.

So now aside from the amazing beaches and rich famous people who are always hanging out, I know it's often called the Marbella of France. So WTF is Marbella?! Help, please.