World's Busiest Cities

The team head to humid Hong Kong, where space is at a premium and real estate is the most expensive in the world.

Dan is in Mexico City to discover the architecture and their delicious street food; Ade tries to get clean drinking water with the citizens.

Dan Snow, Anita Rani, and Ade Adepitan take a look at the systems and people behind the busiest city in Europe: Moscow.

Dan, Anita, and Ade make a trip to India's capital, Delhi, a city with a rising population of 26 million; Anita visits mega markets and learns how the city feeds its residents; Ade takes on the back streets to experience life as a porter.