Your Assuming that all of the Entrances are actually Inside of Law, did it actually state anywhere that that was so? Some of them may be in surrounding Cities, Towns or even Villages of Yves? Even if not originally then it's likely some settlements would form around them. For that matter we don't actually know how many Entrances there actually are? Or that the Royals/Government even know where they all are and has control of them all, although its likely they do unless they are outside of Yves.