Underneath the River Thames, one of the UK's largest-ever underground engineering projects is taking shape. In 1858 the 'Great Stink of London' made much of the city along the River Thames uninhabitable. Between 1848 and 1854 nearly 25,000 Londoners died of cholera, a disease borne by foul water. Joseph Bazalgette saved the city, building sewers that would serve 4 million people and stop waste water emptying into the Thames. These remarkable sewers are still the backbone of London's sewera...