The Tokelau or Union Islands comprise four reef-surrounded atolls lying on a general northwest-southeast line, between lat. 8° and 11° S. and long. 171° and 173° W. They are due north of Samoa and east of the Ellice Islands. The four islands are: Olosenga, or Swain's Island, once known as Quiros' Island; Fakaofu, or Bowditch Island; Nukunono, or Duke of Clarence Island; and Atafu, or Duke of York Island.