The Cirque du Soleil is in London to perform their "Gundam" show and this guy is doing a part of it to cross the Albert bridge.
Cirque du Soleil is really hard to describe except to say that you really really should see it in person. It's way oversimplifying to say that it's a modern circus. It's more abstract than that. Imagine if circus performers were doing what they do not for the purpose of spectacle, but for the purpose of artistic expression. With excellent original music performed live. Imagine being as awed as you are by movie special effects, but seeing them live in a stage show. Imagine sculpture performed.
Aw hell, Cirque is too difficult to describe. I haven't done it yet and I'm just geting started.