The island was erased from official Japanese maps during the war to maintain the secrecy of the poison gas factory.
Workers at the plant were often young students and women who were not fully informed about the lethal nature of the chemicals they were handling.
The museum building itself stands on the site of the former power plant that once fueled the chemical weapons factory.
Many of the island's rabbits are descendants of animals originally released for educational purposes after the factory was decommissioned.
The plant produced over 6,000 tons of poison gas before its destruction by Allied forces in 1945.
Chemical burns and respiratory illnesses were common among the factory workforce, leading to a long-term medical support program for survivors.
The Ōkunoshima Island Poison Gas Museum documents the island's secret history as a production site for chemical weapons during the Second Sino-Japanese War and WWII. The facility details the Imperial Japanese Army's development of mustard gas and lewisite, which were manufactured here under strict secrecy. Exhibits include recovered equipment, protective gear, and testimonies from former factory workers who suffered long-term health complications from toxic exposure. The museum serves as an educational center to warn against the consequences of war and chemical proliferation. It is located on an island now famous for its large population of wild, free-roaming rabbits. The contrast between the dark historical exhibits and the island's current leisure-focused atmosphere is a defining feature of the site.
The red brick ruins of the power plant located just a short walk from the museum entrance.
Visit the surrounding ruins of the former factory buildings, which are located throughout the island and provide necessary context to the museum displays.
Allocate extra time if you wish to feed the rabbits, as the museum is part of a larger island park system.
Wear comfortable walking shoes as the island is hilly and the ruins are spread across a wide area.
Do not chase or feed the rabbits human food, as it is strictly prohibited for the health of the animals.
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Maintain a quiet and respectful demeanor inside the museum given the somber nature of the exhibits.
