What Shoreditch hipsters will tell you is confirmed by the environmentalists. It's east London that makes west London cool.And that perennial role - as temperature regulator rather than fashion barometer - will become increasingly important as the capital comes to terms with the impact of climate change.
London can expect more extreme weather events over the next few years with the number of "uncomfortable" days of heatwave likely to double.
Mason is 10. He looks out on Canary Wharf from his high-rise. He wants to take film-maker David Bond on a tour of his manor, where he takes his dog for a walk to the patch of green that is his meagre playground.