World's Busiest Cities

This time, the team are in Hong Kong, where space is at a premium and real estate is the most expensive in the world. Ade heads into the high rises to find people living in tiny spaces no larger than a cupboard.

Dan Snow, Anita Rani and Ade Adepitan are in Mexico City, uncovering the hidden systems and armies of people that help run it. Anita discovers how they are trying to stop this megacity from drowning in its own waste.

Dan Snow, Anita Rani and Ade Adepitan go behind the scenes to reveal the hidden systems and armies of people running Moscow – a city forged by power and politics.