Each Sunday, TED shares an episode of another podcast we think you'll love, handpicked for you… by us. Today we're sharing a special episode of Far Flung with Saleem Reshamwala.

Harnessing the creativity of a megalopolis isn't easy, but Mexico City shows us how it's done. Follow a real-life superhero who dons a luchador mask and cape to protect his fellow residents from speeding cars, learn how citizens are hacking their way to a better public transport system, and see what it takes to crowd-source a constitution from a city with 21 million minds.