Okino-erabu-jima

, also known as Okinoerabu, is one of the Satsunan Islands, classed with the Amami archipelago between Kyūshū and Okinawa. The island, 93.63 km2 in area, has a population of approximately 14,000 persons. Administratively it is divided into the towns of Wadomari and China in Kagoshima Prefecture. Much of the island is within the borders of the Amami Guntō National Park. Okinoerabujima is isolated from the other Amami islands, and is located in between Tokunoshima and Yoronjima, approximately south of the southern tip of Kyūshū and north of Okinawa. The island is an elevated coralline island with a length of approximately and width of , with Mount Ōyama at above sea level at its highest peak. In the eastern part of the island is an extensive limestone cave system, one of the largest in Asia. The coast of the island is surrounded by a coral reef. Okinoerabujima has a humid subtropical climate (Köppen climate classification Cfa) with very warm summers and mild winters. Precipitation is significant throughout the year, but is somewhat lower in winter. The island is subject to frequent typhoons. It is uncertain when Okinoerabujima was first settled. It was ruled by the Aji nobility who built numerous gusuku fortifications from the 8th century onwards. From 1266 it was part of Hokuzan, and from 1422 the Ryukyu Kingdom. The island was invaded by samurai from Satsuma Domain during the 1609 Invasion of Ryukyu and its incorporation into the official holdings of Satsuma was recognized by the Tokugawa shogunate in 1624. Satsuma rule was harsh, with the inhabitants of the island reduced to serfdom and forced to raise sugar cane to meet high taxation, which often resulted in famine. The island was subordinate to Tokunoshima from 1616 to 1690, when an independent daikansho was established. Throughout the Satsuma period, the island was used as a prison settlement, especially for political offenders, including many members of the Ryukyuan royal family. Saigō Takamori was exiled to Okinoerabujima from 1862 to 1864.