A dejected German Grenadier carrying a machine gun on his shoulder in front of a building on fire during the German retreat in Russia. (Photo by Keystone/Getty Images). 1944

A view of the spectacular colour of clouds at sunset on January 17, 2005 in Beijing, China. (Photo by China Photos/Getty Images)

A policeman stands by a burning car, set alight during a communist march in the East End of London. (Photo by Topical Press Agency/Getty Images). Circa 1936

Clouds float over an open field January 3, 2007 in Shirley Heights, Antigua. (Photo by Joe Raedle/Getty Images)

CANNES, FRANCE - NOVEMBER 03: Italian Prime Minister Silvio Berlusconi leaves the conference centre after the first day of the G20 Summit on November 3, 2011 in Cannes, France. World's top economic leaders are attending the G20 summit in Cannes on November 3rd and 4th, and are expected to debate current issues surrounding the global financial system in the hope of fending off a global recession and finding an answer to the Eurozone crisis. (Photo by Dan Kitwood/Getty Images)

The giant inflatable Rubber Duck installation by Dutch artist Florentijn Hofman floats on the Parramatta River, as part of the 2014 Sydney Festival, in Western Sydney, January 10, 2014. The creation is five stories tall and five stories wide and has been seen floating in various cities around the world since 2007. (Photo by Jason Reed/Reuters)

A pro-independence protester sits in front of Catalonia's regional parliament as lawmakers vote inside, in Barcelona, January 16, 2014. (Photo by Albert Gea/Reuters)

View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)