, officially is the largest of the Okinawa Islands and the Ryukyu (Nansei) Islands of Japan in the Kyushu region. It is the smallest and least populated of the five main islands of Japan. The island is approximately long, an average wide, and has an area of . It is roughly south of the main island of Kyushu and the rest of Japan. It is north of Taiwan. The total population of Okinawa Island is 1,384,762. The Greater Naha area has roughly 800,000 residents, while the city itself has about 320,000 people. Naha is the seat of Okinawa Prefecture on the southwestern part of Okinawa Island. Okinawa has a humid subtropical climate. Okinawa has been a critical strategic location for the United States Armed Forces since the Battle of Okinawa and the end of World War II. The island was under American administration until 1972, and today hosts around 26,000 US military personnel, about half of the total complement of the United States Forces Japan, spread among 32 bases and 48 training sites. History Shell mound eras Early Okinawan history is defined by midden or shell heap culture and is divided into Early, Middle, and Late Shell Mound periods. The Early Shell Mound period was a hunter-gatherer society, with the wave-like opening Jōmon pottery. In the latter part of this period, archaeological sites moved near the seashore, suggesting the engagement of people in fishing. On Okinawa, rice was not cultivated until the Middle Shell Mound period. Shell rings for arms made of shells obtained in the Sakishima Islands, namely Miyakojima and Yaeyama islands, were imported by Japan. In these islands, the presence of shell axes from 2,500 years ago suggests the influence of a southeastern-Pacific culture. After the Late Shell Mound period, agriculture started about the 12th century, and the population center moved from the seashore to higher places. This period is called the Gusuku period. Gusuku is the term used for the distinctive Ryukyuan form of castles or fortresses. Many gusukus and related cultural remains in the Ryukyu Islands have been listed by UNESCO as World Heritage Sites. There are three perspectives regarding the nature of gusukus: 1) a holy place, 2) dwellings encircled by stones, and 3) a castle of a leader of people. In this period, porcelain trade between Okinawa and other countries became commonplace, and Okinawa was an important relay point in eastern-Asian trade. Ryukyuan kings,