Of national and international importance for wildlife conservation, most of Richmond Park (856 hectares; 2115 acres) is a Site of Special Scientific Interest (SSSI), a National Nature Reserve (NNR) and a Special Area of Conservation (SAC). The largest Site of Special Scientific Interest in London, it was designated as an SSSI in 1992, excluding the area of the golf course, Pembroke Lodge Gardens and the Gate Gardens. In its citation, Natural England said: "Richmond Park has been managed as a royal deer park since the seventeenth century, producing a range of habitats of value to wildlife. In particular, Richmond Park is of importance for its diverse deadwood beetle fauna associated with the ancient trees found throughout the parkland. In addition the park supports the most extensive area of dry acid grassland in Greater London."