In 1899, a railway camp was set up in the middle of a swampy plain that the Maasai called Enkare Nyirobi, cool water. There was nothing there. No strategic value, no existing settlement, no reason to build a city. The British chose it because the land was flat enough for a workshop. Within six years, they had declared it the capital of the East Africa Protectorate. Within two decades, it was the largest city in the region. Nairobi was not planned. It was improvised. It sprawled. It grew. Today it is home to five million people.