The Gambier Islands or Mangareva Islands are a small group of islands in French Polynesia, located at the southeast terminus of the Tuamotu archipelago. They are generally considered a separate island group from Tuamotu both because their culture and language are much more closely related to those of the Marquesas Islands, and because, while the Tuamotus comprise several chains of coral atolls, the Gambiers, especially the primary island, Mangareva, are of volcanic origin. Because of their proximity, the Acteon Group, and the nearby atoll of Temoe are sometimes included among the Gambiers.