inaccessible

Inaccessible Island is a volcanic island located in the South Atlantic Ocean, 31 km (19 mi) south-west of Tristan da Cunha. Its highest point, Swale's Fell, reaches 581 m (1,906 ft), and the island is 12.65 km2 (4.88 sq mi) in area. The volcano was last active approximately one million years ago and is now extinct.
Inaccessible Island is a part of the archipelago of Tristan da Cunha, which is a part of the overseas territory of the United Kingdom known as Saint Helena, Ascension and Tristan da Cunha. Tristan da Cunha itself is accessible only by sea via a seven-day voyage from Cape Town, South Africa. The harbour on Inaccessible Island allows access for only a few days of the year. Access to Inaccessible Island must be granted by the local government office.