Ever heard of Ōkunoshima (大久野島)?
It is a small island located in the inland sea of Japan off Hiroshima Prefecture. It is also known as the Rabbit Island, because of the great number of rabbits that roam the island.
However, taking the story to a darker way, this island used to have factories that carried out research on poison gas before and during the World War II.
With the end of the war, documents concerning the plant were burned and Allied Occupation Forces disposed of the gas either by dumping, burning, or burying it, and people were told to be silent about the project. Several decades later, victims from the plant were given government aid for treatment, and in 1988 the Ōkunoshima Poison Gas Museum was opened.