What is the future for Africa's rapidly swelling cities? The stretch of nearly 1,000 km between Abidjan and Lagos, is by 2100 projected to be the largest zone of continuous, dense habitation on earth - and home to about half a billion people. In Ghana alone, the population which was around six million at the time of independence could exceed 50 million by 2050. There has been unprecedented migration into Accra and other cities from rural areas, straining the city’s ability to provide basic housing and services to people, and exacerbating existing inequalities. Presenter Mike Wooldridge and Ghanaian architect Ruth-Anne Richardson report on the opportunities and challenges this rapid urbanisation brings in West Africa.