The island is one of 505 uninhabited islands in Nagasaki Prefecture. The island’s most notable features are its abandoned concrete buildings, undisturbed except by nature, and the surrounding sea wall. While the island is a symbol of the rapid industrialization of Japan, it is also a reminder of its history as a site of forced labor prior to and during the Second World War.
The 16-acre island was known for its undersea coal mines, established in 1887, which operated during the industrialization of Japan. The island reached a peak population of 5,260 in 1959. In 1974, with the coal reserves nearing depletion, the mine was closed and all of the residents departed soon after, leaving the island effectively abandoned for the following three decades.