The Scratch and Sniff experience, April 2011

Dan Snow is bringing the filthy histories of the world's greatest cities to BBC Two, in 'Filthy Cities', an immersive new television series that will bring to life the stinking histories of London, New York and Paris.

Dan will show how these modern capitals were forged in the dirt of the past, emerging from filthy cities to become the iconic modern metropolises we know today. He will step into the shoes of professionals such as the medieval muck-raker responsible for clearing tonnes of excrement from London streets; the pig handler helping to clear the New York streets of waste; and the Parisian undertaker, battling to cope with the human cost of a bloody revolution.

He will meet experts, asking them the questions that never make it into the history books, and put the past to the test by mounting a series of imaginative experiments and thought-provoking stunts to demonstrate the key moments in the fight against filth.

Marrying historical accounts with modern science, and combining ambitious reconstructions with CGI, Dan will build up a picture in deliciously dirty detail of the making of three great capital cities during a pivotal period of the past, and reveal the hidden history behind the modern metropolis.

The Wellcome Trust and BBC have jointly produced a 'Scratch-and-Sniff' experience to accompany the 'Filthy Cities' series and our Dirt Season. Armed with your scratch-and-sniff card, you can watch four short films via the red button on your TV remote or via the Filthy Cities website and you will be transported into the sights and smells of history's filthiest cities with Dan Snow.

Cards will be distributed through BBC magazines, libraries and Dirt Season events at Wellcome Collection and elsewhere. 

Episode one: Medieval London
The City of London is 2000 years old. Every street, every square is built on layer upon layer of history. But London has a hidden past, a filthy secret. This is the story of how 700 years ago the dirt, squalor and disease reached such catastrophic proportions that the medieval authorities would be forced to clean up their act. From the fetid streets of 14th-century London, a new civic pride and spirit of collective cooperation would help a new and cleaner London emerge.

Episode two: Revolutionary Paris
Just 200 years ago Paris was famously one of the foulest and smelliest cities in Europe. Wading through human and animal filth to slave in toxic industries, ordinary Parisians suffered grotesque poverty, sickness and starvation. But after generations of injustice it wasn’t just the conditions that were revolting. Left to drown in their own muck, the citizens of Paris became a mass of filthy discontent, intent on having the King's head.

Episode three: Industrial New York
Almost a million people arrived in Manhattan in the first half of the 19th century from all over Europe. Fleeing persecution, poverty and famine, they came in search of the promised land, what they found was even worse than what they left behind. The Big Apple was rotten to its very core. This is the story of how in fewer than 50 years New York exploded from a country town into a festering metropolis and how a leading global city emerged from this filthy mess.