A Special Area of Conservation (SAC) is defined in the European Commission Habitats Directive (92/43/EEC), also known as the Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora. They are to protect the 220 habitats and approximately 1000 species listed in annex I and II of the directive which are considered to be of European interest following criteria given in the directive. They must be chosen from the Sites of Community Importance by the State Members and designated SAC by an act assuring the conservation measures of the natural habitat.
SACs complement Special Protection Areas and together form a network of protected sites across the European Union called Natura 2000. This, in turn, is part of the Emerald network of Areas of Special Conservation Interest (ASCIs) under the Berne Convention.