Hayley Wood is a 51.7-hectare (128-acre) biological Site of Special Scientific Interest south-east of Great Gransden in Cambridgeshire.

[1][2] It is a Nature Conservation Review site, Grade 1,[3] and it is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire.

[7] Hayley Wood was confiscated from the Bishop of Ely by Queen Elizabeth in 1579 and whenceforth became privately owned.

[8] The structure of Hayley Wood is coppice-with-standards of field maple, ash, hazel and hawthorn species, with a canopy of pedunculate oak and small areas of small-leaved elm.

Oliver Rackham, 1975: Hayley Wood; its history and ecology; Cambridgeshire and Isle of Ely Naturalists' Trust Ltd.