Željava Air Base, situated on the border between Croatia and Bosnia and Herzegovina under Plješevica Mountain, near the city of Bihać, Bosnia, was the largest underground airport and military air base in the former Yugoslavia, and one of the largest in Europe. (Photo by Thomas Windisch/Exclusivepix Media)

With their wings at full length, these beautiful golden eagles soar through the skies in a glorious training session to hunt their prey. Others sit on the arms of their owners and trainers. Batzaya Choijiljav, 41, from Mongolia has taken these magnificent pictures at the annual traditional Kazakhs festival, October 2015. (Photo by Batzaya Choijiljav/Caters News)

Neil Zeller's snaps were taken across Canada, where he photographs the northern lights dancing across a dark night sky. In one stunning shot, Zeller, 42, even manages to capture a flash of lightning beneath a storm cell while an aurora gives off a magnificent green glow. The photographer, from Calgary, Alberta, describes himself as a night person, and became interested in night photography about 10 years ago. (Photo by Neil Zeller/Caters News)

Participants take part in the world's first “Pokemon Go” competition in Hong Kong, China, August 6, 2016. The competition began around 2 in the afternoon local time when organizers began announcing the rules on their Facebook page. Contestants had to take screenshots of 12 specific Pokémon in three different districts. Apart from the 12 key Pokémon, participants could also catch designated rare Pokemons which would take off some minutes from their total time. The winner was 21 year old Frankie Chu. The champ took home roughly three hundred and eighty six dollars that he says he will use to pay his school fees. (Photo by Tyrone Siu/Reuters)

Photographer John Maher, once the drummer with punk bank Buzzcocks, travelled to the Outer Hebrides to photograph abandoned crofters’ cottages – many of which, like this one, have seemingly been untouched since. Here: “Peat Fire”. Taken in March 2013 on the east coast of Harris. The fire is from muir-burning, when farmers burn off grasses and heather to improve grazing for their sheep. (Photo by John Maher/The Guardian)

A man sits in the back of a taxi with a goat after purchasing it from a livestock market ahead of the Eid al-Adha festival in Kolkata, India, September 8, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Philadelphia Phillies Ben Francisco reacts after being hit in the head with a pitch by Cincinnati Reds Logan Ondrusek during the MLB National League Division Series baseball playoffs in Philadelphia, Pennsylvania, United States in this October 8, 2010 file photo. (Photo by Tim Shaffer/Reuters)

A student from “the cliff village” in Atule'er climbs newly-constructed steel ladders after school to go home for holidays, in Liangshan Sichuan province, China, November 19, 2016. The steel ladders which replaced the unsafe vine ladders shortened the time taken for the children to go home, from three hours to two. (Photo by Reuters/Stringer)