The dependency of Tristan da Cunha comprises the islands of Tristan, Inaccessible, Nightingale and Gough with a total land area of 179km2. The islands of the Tristan group (Tristan, Inaccessible and Nightingale lie within 40 km of each other on similar latitudes 2,782 km from Cape Town, South Africa and 3,947 km from Mar del Plata in South America. Gough Island lies 350 km to the south-south-east of the Tristan group. St Helena lies 2,435 km to the north-north-east.
The main island, Tristan is the largest island in the Tristan da Cunha group; roughly circular and 12 km across with an area of 96 km2. It is an active volcano which last erupted in 1961, with a central peak, the highest point being Queen Mary's at 2,060 m above sea level. The volcanic islands are characterised by deep peat mantles and tall, dense vegetation below 500-1,000 m. Lowland areas are dominated by tussock grass, fernbush and bogfern. Shorter fjeldmark and mire vegetation occurs above 500-1,000 m. The climate of Tristan da Cunha is temperate marine, mild and moderated by trade winds.
The population in 1993 was just over 300 people all on Tristan plus a small meteorological team on Gough.