Gough Island, also known historically as Gonçalo Álvares after the Portuguese explorer, is a rugged volcanic island in the South Atlantic Ocean. It is a dependency of Tristan da Cunha and part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha. It is about 400 km (250 mi) south-east of the Tristan da Cunha archipelago, 2,400 km (1,500 mi) north-east from South Georgia Island, 2,700 km (1,700 mi) west from Cape Town, and over 3,200 km (2,000 mi) from the nearest point of South America.