Kirsty Young's castaway is the architectural critic and writer Charles Jencks.

Born in America, for the past four decades he has lived and worked in Britain - where his designs are as likely to be found in sculptural landscapes as buildings. Perhaps his most significant legacy, though, is the work he did with his late wife, Maggie Keswick. They worked together to design Maggie's Centres - a series of practical and beautifully-designed buildings to give information and support to people with cancer.

He says: "When you have cancer, there's many things which you have to do aside from the struggle - it's not just a medical problem, it's a social problem - of how you tell the children, how you tell your boss - and above all, as Maggie said, it's not to lose the joy of living."

Producer: Leanne Buckle.