Ōkunoshima - island, which for many years was absent on official maps of the country, and knew of its existence a few. Even though it is located in the Inner Ōkunoshima sea. Read on here and rabbits.
So Ōkunoshima before the Second World War was the site of dislocation of military spetsbazy where experiments were conducted, and the study of chemical weapons. In particular, mustard gas, which were formally rejected by Japan, according to the signed the Geneva Protocol of 1925. Rabbits were just those on whom experiments were conducted. At the end of the Second World War, the base was closed, and the rabbits released. Now, on an island inhabited by a few hundred rabbits, and even a museum opened hotel.