During the Second World War, the Rocky Mountain Arsenal, near Denver in the USA, developed and produced napalm and mustard gas.
Paradoxically, 50 years on, 'the most polluted spot on earth' is also a unique wildlife reserve and a prime site for the endangered mascot of America - the bald eagle. Presented by Fergus Keeling and Jessica Holm. Producer John Holmes
(Repeated Sunday at 9. 15pm;