The population of the Cairo metropolitan area has increased from less than 6 million in 1965 when the first picture was taken to more than 10 million in 1998 (United Nations Population Division, World Urbanization Prospects). Population densities within the city are some of the highest in the world, and the urban area has doubled to more than 400 square kilometers during that period. Extraordinary rates of population growth are expected to continue, with a predicted population around 14 million by 2015.
For the past few decades, Africans have been moving from rural areas into cities, seeking work. The continent’s urban population has skyrocketed. Nairobi is a prime example of that migration, with its population pushing upward and its boundaries pushing outward.