Dernford Fen
Dernford Fen is a biological Site of Special Scientific Interest north-west of Sawston in Cambridgeshire.
The site is a rare surviving example of rough fen and carr. Other habitats are dry grassland and scrub, together with ditches and a chalk stream. There are breeding warblers, and the diverse habitats are valuable for amphibians and reptiles.
The site is private land with no public access.