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.

Children play at the Ryoji Ikeda exhibition “the transfinite” at the Park Avenue Armory on June 10, 2011 in New York City. The audio visual installation, which will close after tomorrow, features two back-two-back screens displaying a continual loop of sounds, fragments of numbers and strobe-lit patterns that echo the Japanese artist's interest in mathematics, the subconscious and the digital world. (Photo by Spencer Platt/Getty Images)

International photographic competition, which runs in association with the Royal Botanic Gardens in Kew, London, awards special prize for the best close-up images. Here: Winner – Mayflies by Petar Sabol, Goričan, Croatia. (Photo by Sabol Petar/International Garden Photographer of the Year)

An engineer begins the process of conducting a block-by-block inspection of the exterior of the Washington Monument while suspended by ropes September 27, 2011 in Washington, DC. The National Park Service has closed the landmark in the nation's capital indefinitely due to damage caused by a 5.8 magnitude earthquake in August. (Photo by Win McNamee/Getty Images)

The eighth annual Nipponbashi Street Festa stamped Osaka March 20, 2012 (Nipponbashi is Osaka’s geek district – much like Akihabara is for Tokyo). Cosplayers turned up in colourful outfits, dressing as characters from their favourite manga, anime, and video games. The street was closed to cars, and otaku flooded the streets, snapping pics, cosplaying, and hanging out.

Mike Branch helps customers shop for a Halloween masks at Fantasy Costumes on October 28, 2011 in Chicago, Illinois. The store, which had long lines at the registers at 4 AM this morning, is open around the clock through Halloween to help keep up with customer demand. Retailers nationwide are expecting record sales for Halloween merchandise this year with shoppers spending close to $7 billion dollars to celebrate the holiday. (Photo by Scott Olson/Getty Images)

Key Gompa (also spelled Ki, Kye or Kee) is a Tibetan Buddhist monastery located on top of a hill at an altitude of 4,166 metres (13,668 ft) above sea level, close to the Spiti River, in the Spiti Valley of Himachal Pradesh, Lahaul and Spiti district, India. It is the biggest monastery of Spiti Valley and a religious training centre for Lamas. It reportedly had 100 monks in 1855.