The third largest National Park in South Africa, Addo Elephant National Park has expanded to conserve a wide diversity of biodiversity, landscapes, fauna and flora. Stretching from the semi-arid karoo area in the north around Darlington Dam, over the rugged Zuurberg Mountains, through the Sundays River valley and south to the coast between Sundays River mouth and Bushman’s river mouth, Addo covers about 180 000 hectares (444 700 acres) and includes the Bird and St Croix Island groups. Today Addo Elephant National Park is sanctuary to over 550 elephants, lions, buffalo, black rhino, spotted hyena, leopard, a variety of antelope and zebra species, as well as the unique Addo flightless dung beetle, found almost exclusively in Addo.

Only 16 Addo Elephants remained, leading to the proclamation of the park in 1931. The original size of the park was just over 2 000 hectares. Conflicts between elephants and farmers continued after proclamation as no adequate fence enclosed the park. Finally in 1954, Graham Armstrong (the park manager at the time) developed an elephant-proof fence constructed using tram rails and lift cables and an area of 2270 hectares was fenced in. There were 22 elephants at the time. This Armstrong fence, named after its developer, is still used around the park today. Although the park was originally proclaimed to protect a single species, priorities have now changed to conserve the rich biological diversity found in the area.