Ultra Orthodox Jewish men watch a bonfire during the Jewish holiday of Lag Ba-Omer in Jerusalem's Mea Shearim neighbourhood April 27, 2013. Israelis celebrate the Jewish holiday of Lag Ba-Omer, which marks the end of a plague in the Middle Ages that killed thousands of disciples of a revered rabbi in the holy land, by lighting bonfires across the country. (Photo by Ronen Zvulun/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.

A panda bear sits on a logs in a zoo on January 15, 2015 in Hangzhou, China. (Photo by Feature China/Barcroft Media)

A Shi'ite worshiper bleeds after cutting his scalp in a ritual display of mourning during an Ashura commemoration ceremony outside Kadhimiya shrine on December 6, 2011 in Baghdad, Iraq. Ashura marks the death of Prophet Muhammad's grandson the revered Imam Hussein in Karbala, Iraq in 680 AD. Shi'ite festivals were prohibited during the time of Sunni dictator Saddam Hussein's rule. (Photo by Mario Tama/Getty Images)

Men slicing blubber off a large, dead whale. (Photo by Topical Press Agency/Getty Images). Circa 1912

The report, prepared by the Sustainable Development Solutions Network (SDSN) and the Earth Institute at Columbia University, showed Syria, Afghanistan and eight sub-Saharan countries as the 10 least happy places on earth to live. The top 10 this year were Denmark, Switzerland, Iceland, Norway, Finland, Canada, Netherlands, New Zealand, Australia, and Sweden. Denmark was in third place last year, behind Switzerland and Iceland. The bottom 10 were Madagascar, Tanzania, Liberia, Guinea, Rwanda, Benin, Afghanistan, Togo, Syria and Burundi. The United States came in at 13, the United Kingdom at 23, France at 32, and Italy at 50. Here: #8. NEW ZEALAND: A woman dives from a platform into a giant air bed at a park in Palmerston North September 29, 2011. (Photo by Marcos Brindicci/Reuters)

Two woman lie in a puddle of squashed tomatoes during the annual “Tomatina” tomato fight fiesta, in the village of Bunol, 50 kilometers outside Valencia, Spain, Wednesday, August 26, 2015. The streets of an eastern Spanish town are awash with red pulp as thousands of people pelt each other with tomatoes in the annual "Tomatina" battle that has become a major tourist attraction. At the annual fiesta in Bunol on Wednesday, trucks dumped 150 tons of ripe tomatoes for some 22,000 participants, many from abroad to throw during the hour-long morning festivities. (Photo by Alberto Saiz/AP Photo)

An Israeli spectator watches a giant T-Rex balloon during the Purim parade festival in Petah Tikva, Israel, Thursday, March 24, 2016. The Jewish holiday of Purim commemorates the Jews' salvation from genocide in ancient Persia, as recounted in the Book of Esther. (Photo by Oded Balilty/AP Photo)