Kigali, Rwanda: Search for the cleanest city in Africa and the name Kigali will surely pop up! This is a city blessed with a lush green and hilly landscape. The elevation is just high enough to give visitors a wider view of Rwanda’s well laid-out towns, efficient road construction systems and lively urban setting. One reason that Kigali stays so clean: people there strictly frown upon the use of non-biodegradable plastics following a ban on the product in 2008.