Napoli fans celebrate after winning the Coppa Italia final against Juventus FC, in central Naples, Italy on June 17, 2020. Napoli won the Italian Cup with a 4-2 penalty shootout victory over Juventus following a 0-0 draw in a match played at the Rome Olympic Stadium. (Photo by Salvatore Laporta/IPA/Rex Features/Shutterstock)

Coulpe in bed, secret lover hiding. (Photo by Peter Cade/Getty Images)

Secret arrive during the 1st Gaon Chart K-POP Awards at Blue Square on February 22, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Victoria's Secret Angel Martha Hunt celebrates the 2015 What Is s*xy? List in San Diego on September 26, 2015 in San Diego, California. (Photo by Joe Scarnici/Getty Images for Victoria's Secret)

Victoria's Secret model Adriana Lima poses with her Madame Tussaud's wax likeness at a reveal event at the Victoria’s Secret store in Herald Square in the Manhattan borough of New York November 30, 2015. (Photo by Brendan McDermid/Reuters)

A Manchester City fan attends the trophy ceremony after the end of the Soccer Club World Cup final match between Manchester City FC and Fluminense FC at King Abdullah Sports City Stadium in Jeddah, Saudi Arabia, Friday, December 22, 2023. Manchester City won 4-0. (Photo by Manu Fernandez/AP Photo)

Roma's Gianluca Mancini scores his team's goal in the 1-0 Rome derby victory over Lazio at Stadio Olimpico in Rome, Italy on April 6, 2024. (Photo by Alberto Lingria/Reuters)

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.