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.

People look at a 1939 Alfa Romeo 8C 2900B Lungo Touring Spider displayed at Sotheby's in New York City, New York, U.S. July 21, 2016. The car, unveiled in a pre-publicity showing in New York on Thursday, is expected to sell for more than US$15 million – and could set a record for the most money ever paid for a pre-war auto at auction. (Photo by Brendan McDermid/Reuters)

Indian ivory furniture legs in the shape of a goddess from the first century AD are displayed in the 'Afghanistan Crossroads of the Ancient World' exhibition at The British Museum on March 1, 2011 in London, England. Displaying treasures that were in great danger during the years of civil war and Taliban rule, these surviving artifacts reveal Afghanistan's ancient culture, its fragility and its remarkable place in world history. The exhibition opens to the public on March 3 and runs until July 3, 2011. (Photo by Peter Macdiarmid/Getty Images). LONDON, ENGLAND – MARCH 01

“The 1948 Summer Olympics, officially known as the Games of the XIV Olympiad, were an international multi-sport event which was held in London, United Kingdom. After a 12-year hiatus because of World War II, these were the first Summer Olympics since the 1936 Games in Berlin. The 1940 Games had been scheduled for Tokyo, and then Helsinki; the 1944 Games had been provisionally planned for London. This was the second occasion that London had hosted the Olympic Games, the city had previously been the venue in 1908”. – Wikipedia

Photo: The Olympic torch passes through Windsor on its way to Wembley, for the start of the Summer Olympics, 29th July 1948. (Photo by Ron Burton/Keystone/Getty Images)

Second World War veteran 90 year old William Walker launches the Scottish Poppy Appeal, together with soldiers from the Royal Highland Fusiliers, 2nd Battalion the Royal Regiment of Scotland, on October 27, 2011 in Penicuick, Scotland. Mr Walker, who was wounded while serving in Burma in 1943 with the Royal Scots, helped the soldiers form the shape of ninety to celebrate the 90th anniversary of the annual November campaign. (Photo by Jeff J Mitchell/Getty Images)

An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

A man wearing an armor attends a reenactment of the Battle of Agincourt, in Agincourt, northern France, Saturday, July 25, 2015. The French are hosting a reenactment of the clash with England this weekend. More than 800 people in Medieval garb are gathering at the site to commemorate the battle, which was a turning point in the Hundred Years' War. (Photo by Thibault Camus/AP Photo)

A woman carries water during during a visit by a European Union delegation, at an IDP camp in Azaza, east of Ad Damazin, capital of Blue Nile state, October 21, 2015. The camp houses people displaced by war between the Sudan People's Liberation Movement-North (SPLM-N) rebels and the Sudanese government. (Photo by Mohamed Nureldin Abdallah/Reuters)