Tristan da Cunha is a remote volcanic group of islands in the south Atlantic Ocean and the main island of that group. It is the most remote inhabited archipelago in the world, lying 2,816 kilometres (1,750 mi) from the nearest land, South Africa, and 3,360 kilometres (2,088 mi) from South America. The territory consists of the main island of Tristan da Cunha itself, which measures about 11.27 kilometres (7.0 mi) across and has an area of 98 square kilometres (37.8 sq mi), along with the uninhabited Nightingale Islands and the wildlife reserves of Inaccessible Island and Gough Island.
Many of the flora and fauna have a broad circumpolar distribution in the South Atlantic and South Pacific Oceans. Thus many of the species that occur in Tristan da Cunha appear as far away as New Zealand. For example, the plant species Nertera depressa was first collected in Tristan da Cunha,but has since been recorded in occurrence as far distant as New Zealand.
Tristan is primarily known for its wildlife. There are 13 known species of breeding seabirds on the island and two species of resident land birds. The seabirds include: northern rockhopper penguin (Eudyptes moseleyi), Atlantic yellow-nosed albatross (Thalassarche chlororhynchus), sooty albatross (Phoebetria fusca), Atlantic petrel (Pteradroma incerta), great-winged petrel (P. macroptera), soft-plumaged petrel (P. mollis), broad-billed prion (Pachyptila vittata), grey petrel (Procellaria cinerea), great shearwater (Puffinus gravis), sooty shearwater (P. griseus), Tristan skua (Catharacta antarctica hamiltoni), Antarctic tern (Sterna vittata tristanenis), and brown noddy (Anous stolidus). Tristan and Gough Islands are the only known breeding sites in the world for the Atlantic petrel.