Kamikoshiki-jima

 is the second largest island in the Koshikijima Islands. Its coasts are washed by East China Sea. The island's highest peak is Mount Tomekiyama high.
Geography.
The island's mountains are generally raising directly from the sea, with the very small coastal plains. Terrain is rugged, although not to the same degree as on nearby Shimokoshiki-jima. The north-eastern coast features a 5-km long sandspit enclosing three shallow lagoons. The population is concentrated in extreme east of island in the placed on low sandspit 1400 by 250 metres large, being the largest settlement of Japan ever built on the sandspit.
History.
The island was inhabited from the Jōmon period and have an important archaeological sites. It was inhabited by Satsuma Hayato people during Nara period. The first Japanese fortifications on island were built during Jōkyū War in 1221. The island was belonging to Christian domain during Nanboku trade period and islanders has participated in the Shimabara rebellion of 1638. The Kamikoshiki-jima has suffered from the same string of epidemics, famine and typhoon-related damage as nearby Shimokoshiki-jima in 19th and 20th centuries, resulting in significant emigration and population decline which peaked at 11166 men in 1950.
Transportation.
The "Kamikoshiki-jima"' is connected to Nakakoshiki-jima and Shimokoshiki-jima. The bridge and two connecting tunnels at Nakakoshiki-jima were completed on 29 August 2020 after over 9 years of construction.
A ferry lines also connect the Kamikoshiki-jima to the Shimokoshiki-jima island and to the Ichikikushikino city on Kyushu mainland, the latter offering two daily round-trips.
Inside island, the transportation is provided by public buses operating four routes.