Why is it there? Why at the North-East corner of London's Hyde Park? Felons brought condemned down Tyburn Street through jeering cheering crowds in open-backed stake-carts would make their final declaration, their last testament, to those pressing to get a better view at Tyburn Hanging Tree. And this last crowd had come to be impressed. A hanging was a public holiday. A good hanging was carnival. The Hanging Tree is gone these last few hundred years. Instead there is now Marble Arch and traffic roar. But still they come. And still they come to be impressed. Sometimes they are. For this is Speakers' Corner, recognised by UK Act of Parliament in 1872 and since protected, guaranteed -- and where taboos and institutions and whole systems of belief, control, and power are laid open that you might grasp something else, some higher "truth" that's being hard-sold and traded-on in rhetoric and tub-thumping and heckler's best invective. You've got proof. You've refutation. You've got passion, lunacy, conviction. And quite frequently a fair few massive, pathway-crushing crowds waiting for spectacle, for argument that leads back to one or another of those in the thick of it finding they're caught up in their own logic as once a felon was in Tyburn's finest hemp.