Japan's southernmost prefecture, Okinawa Prefecture (沖縄県; Okinawa-ken) makes up the southern half of the Southwest Islands. The prefecture stretches from the southern islands in Kagoshima Prefecture to within 110km of Taiwan. Three island groups make up the prefecture. From north to south, they are the Okinawa Islands, Miyako Islands and Yaeyama Islands.
The northernmost island group is the Okinawa Islands, which contains Okinawa-hontō (meaning 'Okinawa Main Island' in Japanese), home to the prefectural capital, Naha. This is the prefecture's transport hub, easily accessed by flights and ferries to/from the mainland. Plentiful ferries run between Naha and the Kerama Islands, which lie about 30km west of Okinawa-hontō.
Located 300km southwest of Okinawa-hontō, the Miyako Islands are home to the popular beach destination of Miyako-jima. There is no ferry access to this group; you must arrive via flights from the mainland, Naha or Ishigaki.
The Yaeyama Islands, a further 100km southwest, include the coral-fringed island of Ishigaki and the nearby jungle-clad Iriomote-jima. Like the Miyako Islands, you have to fly in.