The Ryukyu Islands , also known as the Nansei Islands or the Ryukyu Arc , are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands, with Yonaguni the westernmost. The larger are mostly volcanic islands and the smaller mostly coral. The largest is Okinawa Island.

Kyūshū is the third-largest island of Japan's four main islands and the most southerly of the four largest islands. In the past, it has been known as Kyūkoku , Chinzei and Tsukushi-no-shima . The historical regional name Saikaidō referred to Kyushu and its surrounding islands. Kyushu has a land area of 36,782 square kilometres (14,202 sq mi) and a population of 14,311,224 in 2018.