In a fascinating three-part series, Andrew Marr  reveals how these heaving mega-metropolises  feed, protect and move their citizens. From the
gleaming  skyscrapers of Shanghai to Dhaka’s toughest slum, from London, the grand old man of metropolises, to the colourful streets of Mexico City and hi tech Tokyo. 

Andrew discovers how the megacity defines every aspect of its inhabitants daily lives and asks if the  future of megacity is the future of the human planet.