A pair of young visitors rushes through a tunnel of colored lights at the annual Garden of Lights display at Brookside Gardens on December, 06, 2015 in Silver Spring, MD. (Photo by Bill O'Leary/The Washington Post)

Only after World War II did the secret spill: Ōkunoshima, located in the Inland Sea of Japan between Hiroshima and Shikoku, was the top-secret site for manufacturing chemical warfare. When the factories were closed down, a number of exotic wild rabbits were seen freely roaming the island. They were assumed to have been the test subjects for the chemical weapons, which the military failed to eradicate when the factory was demolished.

A groundskeeper uses a bamboo broom at Kasumigaike Pond at Kenrokuen Garden in Kanazawa, Japan on January 12, 2016. The japanese garden, located next to Kanazawa Castle, encompasses over 28 acres in downtown Kanazawa. With two ponds, rolling hills with streams and bridges, is considered a strolling-style landscape garden. It's regarded as one of the top three most beautiful gardens in Japan. (Photo by Linda Davidson/The Washington Post)

A mischievous squirrel chases a turkey in a garden in Medford, Wisconsin in the second decade of January 2024. The garden’s owner, artist Cheryl Plautz, said the squirrels chase the birds “for fun”. (Photo by Cheryl Plautz/Solent News)

Japanese macaques are relaxed in an outdoor hot spring bath at Hakodate Tropical Botanical Garden on December 1, 2016 in Hakodate, Hokkaido, Japan. The garden offers the hot spring treatment to macaques until May next year. (Photo by The Asahi Shimbun via Getty Images)

A couple enjoys viewing illuminated autumn leaves with projection mapping at Shinjuku Gyoen National Garden during a preview at the garden in Tokyo, Japan on November 22, 2023. The illumination will start on 22 November through 03 December 2023. (Photo by Kimimasa Mayama/EPA/EFE)

Dancers perform inside of transparent balls during the Botanical Night at Botanical Garden in Berlin, Germany, 20 July 2018. During the Botanical Night a 16 kilometre long path along the flower beds and several themed gardens are illuminated and guide to many attractions. (Photo by Hayoung Jeon/EPA/EFE)