The Ravens of the Tower

Right now, inside a fortress that William the Conqueror built nearly a thousand years ago, six black ravens are sitting on the lawn at the Tower of London like they own the place. And in a way, they do. There's an old prophecy — nobody knows exactly how old — that says if the ravens ever leave the Tower, the Crown will fall and Britain with it. It sounds absurd. But for over three centuries, the British government has refused to take the chance.