African Cities and Towns before the European Conquest, by Richard W. Hull (TPB, 1976, $1.75)
Ok, I will admit to ignorance. I had no idea there were cities in Africa before the Europeans came. There were. Great urban civilizations existed in the cities of Great Zimbabwe, Benin, Timbuktu, Safala, and Kano. If you were as ignorant as I was, you need to read this book. Look for it in the African section, avail. 11/2.