A climber walks on the ridge beneath the eastern peak of the Gamsberg (2385 meters above sea level) near Grabs, Switzerland, Friday, October 3, 2014. (Photo by Gian Ehrenzeller/AP Photo/Keystone)

Indonesian students wearing paper masks take part in the East Java Mask Parade in Surabaya, Indonesia, 13 December 2015. Thousands of people participate in the traditional parade to preserve the mask custom among the younger generation. (Photo by Fully Handoko/EPA)

Rowers enter in Canaregio river during the 42nd Venice Vogalonga on May 15, 2016 in Venice, Italy. 42 years ago a group of Venetians, both amateur and professional rowers, came up with an idea of non-competitive race in which any kind of rowing boat can take part. The first Vogalonga began with the message to protest against the growing use of powerboats in Venice and the swell damage they do to the historic city. (Photo by Awakening/Getty Images)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

A spotted owlet appears to be playing peek-a-boo near Rancharda Lake in Ahmedabad, India on February 9, 2016. The species is common across the Indian subcontinent. (Photo by Caters News Agency)

Blow-up unicorns, a pig on a pulley and chickens on the lam populate the polychrome pictures in this year’s LensCulture street photography awards. Here: Subida Al Cielo, by José Nieto. Finalist, single image. (Photo by José Nieto/LensCulture 2018 Street Photography Awards)

“Red Land: Sunset Cloud Village is one of the most picturesque places in Red Land, China. As its name indicates, it's best to see before sunset. The reddish brown soil turns redder after rainfall and after farmers plow the land”. (Photo and comment by Peng Jiang/National Geographic Photo Contest via The Atlantic)

A vervet monkey passes in front of a woman on the shores of lake Naivasha, Kenya January 24, 2017. (Photo by Goran Tomasevic/Reuters)