A masked tourist poses for a souvenir photo next to a graffiti titled “Mobile World Virus” depicting “La Gioconda”, aka Mona Lisa, with a mobile phone and a medical mask, by urban artist TVBoy, close to the Sant Jaume square in Barcelona, Spain, 09 March 2020. Barcelona's Deputy Mayor and two town councillors are in quarantine after they were in contact with a City Hall's worker who was tested positive for the COVID-19 coronavirus. (Photo by Quique Garcia/EPA/EFE)

A Sri Lankan man use a scarf as a protective mask as he waits for a swab test at a locked-down area in Colombo, Sri Lanka, 14 May 2020. The Sri Lankan government has started lifting most of the restrictions implemented nearly two months ago in a bid to slow down the spread of the SARS-CoV-2 coronavirus causing the COVID-19 disease and is preparing for a full reopening of businesses and a resumption of activities to avoid an economic slump. (Photo by Chamila Karunarathne/EPA/EFE/Rex Features/Shutterstock)

Visitors look out from a balcony in a quiet mall area with closed retail shops and restaurants only offering takeaway on Tuesday, May 10, 2022, in Beijing. China's capital began another round of three days of mass testing for millions of its residents Tuesday in a bid to prevent an outbreak from growing to Shanghai proportions. (Photo by Ng Han Guan/AP Photo)

BAZ-69092-012 special wheeled chassis. Exhibition of military vehicles at Bronnitsy test range (a town in Moscow Oblast, Russia, located 54.5 kilometers (33.9 mi) southeast of central Moscow). Juny 10, 2011. (Photo by Vitaly Kuzmin)

A visitor to The Brooklands Double Twelve Motorsport Festival admires a 1914 Morgan Three Wheeler in front of a Hawker P1127 prototype jet aircraft on June 18, 2011 in Weybridge, England. Two hundred vintage cars are competing in various races, tests and speed trials over the two day event held at the Brooklands Museum. Brooklands was the world's first purpose-built, permanent motorsport venue that opened in 1907. (Photo by Peter Macdiarmid/Getty Images)

A student of the Sri Lankan ancient martial art “Angampora” performs during a practice session at the angam maduwa or fighting field, in Korathota, a suburb of Colombo, Sri Lanka, 07 September 2022. Sri Lanka's ancient martial art, Angampora, is thought to be thousands of years old. Anga translates to “body parts” and Angampora is a fighting art that uses body parts. Martial arts practitioners in Angampora were mostly in the king's service, and they were tasked with protecting the king and his kingdom. Angampora was practiced in secret for most centuries because the British, who colonized Sri Lanka, banned it in 1818 after seeing it as a threat. (Photo by Chamila Karunarathne/EPA/EFE)

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.