National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

“After an afternoon of hiking and exploring the caves of Rhossili Bay, West Glamorgan, we caught the sun breaking through the clouds”. (Photo by Megan Warren-Davis/The Guardian)

This stirring collection of photos which offer a glimpse behind the scenes of army life have all been selected as winners in an annual competition. The remarkable pictures in the Army Photographic Competition show Britain's soldiers at work and play. They have been taken by amateur and professional soldier cameramen and include images from operations in Afghanistan, air shows and sporting events. The winners were announced at a ceremony held at the Army Headquarters in Andover in Hampshire. (Photo by Jamie Peters/MoD/Geoff Robinson Photography/REX Features)

A motorway bridge crosses the icy Hunhe River in Shenyang, China on December 12, 2019. (Photo by Costfoto/Barcroft Media)

Military planes fly above a statue of Soviet Union founder Vladimir Lenin during a Naval parade rehearsal in St. Petersburg, Russia, Thursday, July 25, 2019. The celebration of Navy Day in Russia is traditionally marked on the last Sunday of July and will be celebrated on July 28 this year. (Photo by Dmitri Lovetsky/AP Photo)

American model Emily Ratajkowski and Vanessa Hudgens attend the 73rd Annual Tony Awards at Radio City Music Hall on June 09, 2019 in New York City. (Photo by Mike Coppola/Getty Images for Tony Awards Productions)

This handout picture released by Jordan's Aqaba Special Economic Zone Authority (ASEZA) on July 23, 2019 shows a Jordanian Armed Forces armored vehicle lies on the seabed of the Red Sea off the coast of the southern port city of Aqaba, part of a new underwater military museum. (Photo by Aqaba Special Economic Zone Authority via Reuters)