Ashridge Commons and Woods is a 640.1 hectare biological Site of Special Scientific Interest in Buckinghamshire and Hertfordshire.

It is located in Little Gaddesden, and is part of the National Trust Ashridge Estate in the Chilterns Area of Outstanding Natural Beauty.

[1][2] This site is mainly semi-natural vegetation, with has extensive areas of woodland, grass and scrub.

Other species which are locally rare are common redstart, nightingale and wood warbler.

There are a number of small ponds which support populations of amphibians and invertebrates.