In England, Sites of Special Scientific Interest (SSSIs) are designated by Natural England, which is responsible for protecting England's natural environment.
Designation as an SSSI gives legal protection to the most important wildlife and geological sites.
This 2-kilometre (1.2-mile) long site is calcareous fen.
There is a large area of wet grassland, which is grazed by cattle, and a small area of carr woodland.
Meadow flora include cowslip, dyer's greenweed and pepper-saxifrage.