Africa is home to the 10 fastest growing cities in the world. Over the next 25 years, the World Bank projects that the continent's urban population will double to 1 billion.
Yet along with gleaming skyscrapers and shopping malls, African cities are feeling growing pains. More than half of the 4 million people in the Kenyan capital Nairobi live in slums, often without access to running water, electricity or sewage systems. Traffic in Nairobi and other booming cities has become nightmarish.
On this edition of Global Journalist, a look at the huge planning and infrastructure challenges for African cities as they undergo one of the most rapid periods of urbanization in world history. Will tomorrow's African megacities be economic powerhouses or giant slums?