After more than a half century of separation, public health issues have returned to the urbanism discussion. But what is a healthy city? In an illuminating interview with Metropolis Magazine, renowned architect and designer Jan Gehl offers his insight from more than 50 years of studying people and the spaces they love. He has found that sustainability and health are intrinsically related and that the cities that best address these issues are those that look at buildings and life simultaneously. They are also designed for people, rather than cars.