Site of Special Scientific Interest

conservation designation denoting a protected area in the United Kingdom

A Site of Special Scientific Interest (SSSI) is a type of legal conservation given to an area in the United Kingdom. They are sites of biological or geological interest, or both.

Arlington Reservoir, a 99.4 hectare (245.6 acre) biological SSSI in Arlington, East Sussex

Any activity which might affect an SSSI is illegal unless the appropriate planning body gives permission. Owners of land must do what needs to be done to protect an SSSI which sits on their land. There may be grants available to help owners look after the site.