Kenya's Kakuma refugee camp is one of the world's largest, home to over 100,000 people drawn from across east and central Africa. Though notionally still a 'temporary' camp, it has become a permanent urban space in all but name with businesses, schools, a hospital and its own court system. Such places, Bram J. Jansen argues, should be recognised as 'accidental cities', a unique form of urbanization that has so far been overlooked by scholars.