For the first time in human history more than half of us live in cities. Vibrant, complex, colossal - what drives their success? Singapore is a city that's had to be resourceful to be successful. One of only 3 city-states in the world, it's built on the faultlines of Southeast Asia. In one day in a city that thinks differently, we dive a coral reef to understand how to safeguard the city's future; meet the chef running 60 restaurants a day; and see how they keep their water sweet. Show less