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)

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)

Maksym Demchuk of Ukraine takes part in the FAI World Hot Air Balloon Championship near Gross-Siegharts, Austria on August 20, 2018. (Photo by Heinz-Peter Bader/Reuters)

Visitors play in front of hot air balloons during the 2016 International Hot Air Balloon Festival in Taitung, southeast of Taiwan, 01 July 2016. Thirty-one hot-air balloon teams from 14 countries join the six days of competition during the festival, which will run from 01 July to 07 August 2016. (Photo by Ritchie B. Tongo/EPA)

Sukhoi Su-30SM jet fighters of the Sokoly Rossii (Falcons of Russia) aerobatic team fly in formation during the International Army Games 2016, in Dubrovichi outside Ryazan, Russia, August 5, 2016. (Photo by Maxim Shemetov/Reuters)

Couples compete in the Salon Tango style qualifier round at the Tango World Championship in Buenos Aires, Argentina, August 22, 2016. (Photo by Enrique Marcarian/Reuters)

Workers prepare Koshary, a popular Egyptian dish, in an attempt to break the Guinness World Record for the world's biggest plate of Koshary, at a general garden in Zamalek, Cairo, January 17, 2015. Koshary is a traditional Egyptian dish dating to the 19th century in which rice, pasta and lentils are mixed together in one plate with a topping of spicey tomato sauce and some crispy fried onions. With a huge plate of koshary measuring 10 metres long and in width and of 1.2 metres in height, the plate weighed 7 tonnes, or about 7,000 kg. About 6,000 attendees turned up to the festival, earning it a place in the world record books. (Photo by Mohamed Abd El Ghany/Reuters)

A young protester takes part in a protest near Tahrir Square to call for the fall of Islamist President on January 24, 2012 in Cairo. (Photo by Mohammed Abed/AFP Photo via The Atlantic)