World's Busiest Cities

This time, they are in Hong Kong, where space is at a premium and real estate is the most expensive in the world, so Ade heads into the high rises to find people living in tiny spaces no larger than a cupboard. This former British colony, handed back to the Chinese in 1997, is a city driven by trade and commerce and Dan discovers how it is adapting to life in China's embrace, while Anita learns about the city's many traditions - from bamboo scaffolding to banishing bad spirits on the daily commute. Ade heads to the races at Happy Valley, and Dan discovers the history of the origins of the Hong Kong and Shanghai Banking Corporation - HSBC. Hong Kong is crowded, chaotic and facing an uncertain future. How does this city of contrasts manage the delicate daily balancing act that keeps it on track?

This time, Dan Snow, Anita Rani and Ade Adepitan are in Mexico City, uncovering the hidden systems and armies of people that help run this sprawling megalopolis of over 22 million people. It is crowded, it iscongested and this haphazard city sits in a major earthquake zone, but the people here have a strength of spirit that allows them to defy everything nature can throw at them.

Anita discovers how they are trying to stop this megacity from drowning in its own waste, while Ade heads to the edge of the sprawl to find out about the daily struggle for clean, affordable drinking water. Dan reveals how you build a skyscraper in an earthquake zone and learns the hard way that Mexican street food can be hot! Mexico City has grown at a staggering pace. How on earth does this epic sprawl survive its many daily battles?

This time, Dan Snow, Anita Rani and Ade Adepitan are in Moscow revealing the hidden systems and armies of people that help run the biggest and busiest city in Europe.

Capital of Russia, this is a city of 13 million people that likes to play by its own rules. It is also a place of contradictions - where the most efficient metro system in the world meets the worst traffic jams on the planet. Anita goes bumper to bumper in this city of epic commutes, while Ade discovers how Muscovites escape the stresses of city life with a trip to a dacha - there is vodka, a Russian sauna known as a banya, a thrashing with birch leaves and... more vodka. And, in this city forged by power and politics, Dan gets privileged access to one of Moscow's most closely guarded secrets - going behind the closed doors of the Kremlin, before heading underground to see one of the biggest metro expansion projects in the world. Moscow is crowded, it is imposing and it radiates military might. How does this city of nearly 13 million people reconcile a communist past with their capitalist present?

This time, they are in Delhi, capital of India, with a population of 26 million and rising. Anita discovers how this growing city feeds itself, visiting Asia's largest fruit and veg market, a round-the-clock operation spanning an area the size of 80 football pitches turning over a billion pounds a year.

Dan explores how the city has grown from its origins at the heart of the great Mughal Empire, through jewel in the crown of the British Raj to capital of the world's largest democracy, while Ade braves the seething backstreets to get a taste of life as a porter in one of India's oldest markets. It is hectic, it is noisy and it is hot. How on earth does this city of 26 million people live, thrive and survive?