Danger, Keep Out!
That's the sign outside the Chemical Defence Establishment at Porton Down, scene of this month's Radio Nature Trail. But where human beings are forbidden to enter, animals and plants can live in conditions now rare in our crowded countryside.
Introduced by DEREK JONES
Producer DILYS BREESE (Bristol) (Repeated: Wednesday, 9.5 am. Wildlife: Monday, 10.5 am)