A young woman employee of North American Aviation Incorporated, working over the landing gear mechanism of a P-51 fighter plane, Inglewood, California, 1942. (Photo by Alfred T. Palmer/Buyenlarge/Getty Images)

Ruins of a building are seen in the old village of Belchite, in northern Spain, November 13, 2016. Almost 80 years ago Tomas Ortin fled under the cover of night from his home in the small town of Belchite on Spain's northern plains to escape with hundreds of others from one of the bloodiest battles of the country's civil war. At 94 years old, Ortin now lives just across the road from Belchite, which has lain in ruins since Republican forces attacked it, a symbol of the destruction caused by the 1936-1939 war in which an estimated 500,000 people died. (Photo by Andrea Comas/Reuters)

An Israeli tank moves into position in the Israeli controlled Golan Heights during fighting between forces loyal to Syrian President Bashar Assad and rebels in the Druze village of Khader in Syria, Tuesday, June 16, 2015. As many as 20 members of the Druze minority sect were killed last week, the deadliest violence against the Druze since Syria's conflict started in March 2011, sparking fears of a massacre against the sect. (AP Photo/Ariel Schalit)

“Light From Heaven”. Taken around Mount Bromo, East Java, Indonesia in the morning. Photo location: East Java, Indonesia. (Photo and caption by Pimpin Nagawan/National Geographic Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

“Locusts & Men”. Oppression, interaction, collaboration. In the life cycle of nature nothing is lost, but the coexistence of different species is sometimes difficult. In Madagascar periodically returns the archaic antagonism between man and the migratory locust, in a circle of life where the two species are looking for space and food for their survival. At the end of the day a man walks home carrying on his shoulders the heavy bag which contains the locusts captured during the day. The insects provide nutritious meals for the man and his family. Photo location: Madagascar, 2013. (Photo and caption by Michele Martinelli/National Geographic Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

“Say cheese”. Cheetahs jumped on the vehicle of tourists in Masai Mara national park, Kenya. (Photo and caption by Yanai Bonneh/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

German field telegraph operators at work in Warsaw. (Photo by Hulton Archive/Getty Images). 1st October 1914

Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)