Ōkunoshima is a small uninhabited island in Japan, between the cities of Hiroshima and Shikoku, which houses a hotel and a museum of the toxic gas factory opened in 1988. However, the island has become popular for its large colony of rabbits, introduced between the 1930s and 1970s to test the effects of the gas.
Today hundreds of rabbits live free and roam undisturbed among the visitors. Until the first Sino-Japanese war the island was entirely cultivated; fortifications were then built to defend it. In 1929 the Japanese government, despite the Geneva Convention banning them in 1925, secretly installed a poisonous gas factory here, in particular mustard gas, for use in chemical weapons, closed only at the end of the Second World War.
Given the secrecy of the military program, Ōkunoshima was even erased from the maps. The resident population and all those who worked on the program were able to keep the chemical activity a secret throughout that historical period.
The island was chosen for its isolation, conducive to greater security, and for its remoteness from Tokyo and other sensitive areas in the event of an accident. Under the jurisdiction of the Japanese Army, a fish packing plant has been transformed into a poison gas production unit.
Residents and prospective employees were not notified of this change and everything was kept secret. The working conditions were grueling and many people suffered from diseases related to exposure to toxic products.
Ōkunoshima: the rabbit island, but in Winter...
The first rabbits were introduced to Ōkunoshima in the early 1930s and remained there until the Second World War, when the small and secluded island was elected as a laboratory for research and production of chemical weapons to be used during the conflict.
Today the island is uninhabited, but it houses a hotel and a museum dedicated to the toxic gas factory. It is also called Usagi Shima because it hosts a large colony of rabbits, as mentioned above, probably introduced in 1971 by a group of students.
Administratively it is part of the municipality of Takehara, and is connected by ferries to the ports of Tadanoumi and the island of Ōmishima. In fact, the place attracts around 100,000 visitors every year, who reach it in the summer for its beaches, onsen and its small resort.
It also has a small but well-equipped visitor center and a camping area. Feeding is a problem for these rabbits: today rabbits are also often fed by visitors, who populate the island during the summer months. In the cold months, when the island is not frequented and the vegetation offers little to the small inhabitants, it leads to an irregular diet that causes a rather short life expectancy in the Ōkunoshima rabbits.