Query: what type of islands are the Tristan da Cunha
Context: Tristan da Cunha /ˈtrɪstən də ˈkuːnjə/, colloquially Tristan, is both a remote group of volcanic islands in the south Atlantic Ocean and the main island of that group. It is the most remote inhabited archipelago in the world, lying 2,000 kilometres (1,200 mi) from the nearest inhabited land, Saint Helena, 2,400 kilometres (1,500 mi) from the nearest continental land, South Africa, and 3,360 kilometres (2,090 mi) from South America.