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 newborn baby giraffe shows its tongue at the Planckendael zoo in Mechelen, 25 kilometers North of Brussels, Tuesday, February 18, 2014. The calf was born on Valentines day, February 14, and has a heart shaped spot on the hip. (Photo by Yves Logghe/AP Photo)

Residents observe a police officer take up position during an operation at the Mare slums complex in Rio de Janeiro March 25, 2014. The federal troops have taken control of security operations in Mare slums complex to help quell a surge in violent crime following attacks by drug traffickers on police posts in three slums on the north side of the city, government officials said. (Photo by Ricardo Moraes/Reuters)

Passengers from the ferry sinking off South Korea's southern coast are rescued by the South Korean Coast guard in the water off the southern coast near Jindo, south of Seoul, on April 16, 2014. Almost 300 people were missing after a ferry sank off South Korea on Wednesday, the coastguard said, in what could be the country's biggest peacetime disaster in nearly 20 years. (Photo by AP Photo)

“Only the most intrepid urban explorers cross the tattered ruins of the old Iron Curtain to endure the excessive bureaucracy, military paranoia and freezing winds of the East to hunt for the ghosts of an empire. Rebecca Litchfield is one who couldn't resist the haunting allure of the ruins of the Soviet Union”. – Yahoo News. Photo: Hungary, MAV 424 Steam Train. (Photo by Rebecca Bathory)

“Mountain Goats, Colorado”. A herd of mountain goats huddle together on top of Mount Evans, Colorado during a lightning storm. This photo was selected out of more than 5,000 entries to go on display in “Wilderness Forever: 50 Years of Protecting America’s Wild Places”, a new photo exhibition at the Smithsonian’s National Museum of Natural History, which will run through summer 2015. (Photo by Verdon Tomajko/Smithsonian Wilderness Forever Photo Contest)

“Adventurers have gone deep underground to discover previously unexplored caves in these pictures. The awe-inspiring snaps show the cavers dwarfed by the huge series natural rock chambers in the Leye – Fengshan Geopark, China. Belgian photographer Francois-Xavier De Ruydts, 33, captured the team of explorers as they trekked through the deep wonderground in January 2014”. – Caters News. Here: Caving expedition in Fengshan, China, Guangxi province. (Photo by Francois-Xavier De Ruydts/Caters News)

Juan Carlos Vilchez, 18-months-old, dressed to represent horror movie icon Chucky, looks into a storefront mall window, in Managua, Nicaragua, Friday, October 31, 2014. Juan Carlos is wearing a first place winner that he won earlier, for best Halloween costume in his age group. (Photo by Esteban Felix/AP Photo)