Afghan children wait as their mothers receive treatment at a USAID-funded health center on September 7, 2011 in Farza, Afghanistan. Almost 10 years after the 9/11 attacks and the U.S. invasion of Afghanistan, the U.S. government funds some of 500 Afghan health facilities nationwide, most run by non-governmental organizations contracted by the Afghan Ministry of Public Health. (Photo by John Moore/Getty Images)

Vehicles clog a highway during a hazy day in Beijing, China, Wednesday, February 26, 2014. Beijing remained cloaked in hazardous white pollution hiding much of its skyline Wednesday, despite the announced closures or production cuts at 147 of the city's industrial plants. (Photo by Ng Han Guan/AP Photo)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

A bride weeps in a mass wedding ceremony at the CheongShim Peace World Center in Gapyeong, South Korea, Wednesday, February 12, 2014. Some 2,500 South Korean and foreign couples exchanged or reaffirmed marriage vows in the Unification Church's mass wedding arranged by Hak Ja Han Moon, wife of the late Rev. Sun Myung Moon, the controversial founder of the Unification Church. (Photo by Lee Jin-man/AP Photo)

Labrador puppies “Hoey” (L) and “Hatton”, named in honor of September 11, 2001 attack victims Patrick Hoey and Lenny Hatton who died in the World Trade Center, are pictured on the grounds of the Pentagon near Washington, June 28, 2011. (Photo by Jason Reed/Reuters)

Professional conceptual category winner. Greetings from Mars, by Julien Mauve, France. Mauve says: “I have always wondered what it would be like to discover a totally different world ... and to photograph it for the first time as if I was Ansel Adams. So I came up with this project, which is about space exploration and discovery. But it’s also about our behavior in front of landscapes and how we create pictures that will share our personal story with the world”. (Photo by Julien Mauve)

Kazakh troops march during a parade of the armed forces to mark the Defender of the Fatherland Day in Astana, May 7, 2014. (Photo by Mukhtar Kholdorbekov/Reuters)

These heart-warming photograph show an incredible bond between a wild lioness and the men fighting to save her species. The picture show Sirga – a 110lb lioness – and her adopted pride Valentin Gruener (not pictured) and Mikkel Legarth. Incredibly she treats the two men just like she would other lions and with their help she can now hunt for prey on her own. As a cub she was driven out from a pride and rescued by German and Danish duo Valentin and Mikkel who could not stand by and watch her die. She is now a beacon for hoped success of the Modisa Wildlife Project, founded in Botswana, Africa, by Valentin and Mikkel with the hope of saving the lion population. (Photo by Caters News)