Fighters of the Free Syrian Army fire an anti-aircraft weapon in the rebel-held Mashhad area in southeastern Aleppo, on December 12, 2016, as they battle Syrian government forces during an operation to retake the embattled city. The crucial battle for Aleppo entered its “final phase” after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad. (Photo by AFP Photo/Stringer)

The sun rises over the River Brue on the Somerset Levels as temperatures in parts of the south west drop below freezing, on January, 20, 2015. (Photo by Ben Birchall/PA Wire)

Of the epic landscape, the California-based photographer said: “It was an incredible moment and I'm just glad I decided that day to pick up my camera and give it a go because I don't know if I will ever get the chance again”. (Photo by Nolan Nitschke/Caters News)

Two people wearing animal costumes join others as people gather to celebrate the Winter Solstice at Stonehenge in England Tuesday December 22, 2015. The winter solstice is celebrated by many people around the world as the beginning of the return of the sun. (Photo by Ben Birchall/PA Wire via AP Photo)

Wingsuit flyer contestant Melissa Pemberton of the U.S. jumps off a mountain at Tianmen Mountain National Park in Zhangjiajie, Hunan province October 19, 2014. (Photo by Reuters/China Daily)

People at a Czech Stop look at a cloud of smoke rising from the explosion in West, Texas, April 17, 2013. (Photo by Andy Bartee via Dallas Morning News/MCT)

A Tibetan girl reacts as she gets ready to perform in a function organised to mark “Losar” or the Tibetan New Year in Kathmandu, Nepal, February 11, 2016. (Photo by Navesh Chitrakar/Reuters)

Korean War veteran Jon Sun Rye, 83 years old, walks after she paid respect to former leaders Kim Il-sung and Kim Jong-il at Mansu Hill in Pyongyang, North Korea, 15 April 2016. North Korea is marking the “Day of the Sun”, celebrating the day of birth of the country's founder, Kim Il-sung. The Day of the Sun is a national holiday. (Photo by Franck Robichon/EPA)