The furthest north of them, 50 km (31 mi) northeast of Ureparapara, is Vet Tagde (also known as Vot Tande or Vat Ganai), which is an extinct volcano that last erupted 3.5 million years ago.Mota Lava is the largest and highest (411 m) of this eastern chain of islands; off its southern coast, attached by high corals that can be waded through at low tide, is the tiny islet of Ra.The principal economic activity is subsistence agriculture, although copra, coffee and (on Gaua) cacao are grown for export.Like the rest of Vanuatu, the Banks Islands were first settled around the 12th century BCE by Austronesian navigators belonging to the Lapita culture.[3][4] Between 25 and 29 April 1606, the Banks Islands became the first part of Vanuatu to be discovered by a European explorer: A Spanish expedition led by the Portuguese explorer Pedro Fernández de Quirós sailed past Merelava and stopped at Gaua before landing on Espiritu Santo and establishing a short-lived colony there.