Copenhagen, Denmark
Before the 1960s, Copenhagen was a city renowned for cars, traffic jams and pollution. Today, it has the longest pedestrianised street in the World (Strøget), it has been called the most liveable city in the World and it has a realistic vision to become the World's best cycling city.
That's some turnaround.
Do you want to find out more about what they did and how? There's a little more in some of my blog posts: