Clare Balding explores six great historic walking routes of the British Isles. 4: The Icknield Way Every lump and bump on the landscape has a history, as Clare learns from Susan Oosthuizen when they walk from Steeple Morden to Therfield Heath in Cambridgeshire. See OS Maps Explorer 208 and 209. Producer Lucy Lunt. PHONE: [number removed] For a factsheet send a large SAE to: [address removed] E-MAIL: ramblings@bbc.co.uk