Wakilan Deutsche Welle sun kai ziyara a manyan-manyan biranen duniya da ake yiwa laƙabi da Megacities, ciki har da biranen Legas a Najeriya da Alƙahira a Masar, inda suka zanta da shahararrun mawallafa. Shirin wannan karon ya duba birnin Alƙahira ne.