Will Self on the pleasure of walking without purpose, with no final destination in mind, and the freedom that comes from getting lost once in a while.

He reflects on the rising perception that our public spaces are becoming ever more threatening - especially for women.

'Our movements about this wide and wonderful world are for the most part painfully constrained,' he writes. 'Comfort zones have become more and more constricted'.

He argues that there are many reasons for this, including the grim revelations in recent years about the criminal activities of police officers.

Producer: Adele Armstrong Sound: Peter Bosher Production coordinator: Helena Warwick-Cross Editor: Richard Fenton-Smith