Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

German Nazi leader Adolf Hitler (1889 - 1945) enjoys a quiet picnic between meetings, circa 1933. Picture 196 of a series of collectable images published in Germany during the Nazi period, entitled “Deutschland Erwacht” (Germany Awakes). (Photo by Heinrich Hoffmann/Hulton Archive/Getty Images)

An air raid drill at Seattle College caught students William Bates, left, and Edna Mae Farrell, right, while they were eating their lunch in the school café, but they simply took shelter under the table and continued eating in Seattle, Washington, March 17, 1942. Air raid wardens said 350 students left their classrooms and assembled in shelters within one minute in first at the college. (Photo by AP Photo)

Model Daisy-May Demetre, 9 year-old double amputee who will walk the runway during Paris Fashion Week, is seen during a photo shoot a day before the show of luxury children's wear label Lulu et Gigi in Paris, France, September, 26, 2019. (Photo by Gonzalo Fuentes/Reuters)

A child carrying a small broom walks by a line of National Guard members deployed to Bellevue Square as community members clean up after looting and vandalism that occurred Sunday at Bellevue Square in downtown Bellevue, Washington, U.S. June 1, 2020. (Photo by Lindsey Wasson/Reuters)

An Orthodox child is given an icy dip in a lake in celebration of Epiphan, near the village of Vorontsovka, some 20 km from the Kyrgyz capital of Bishkek, Kyrgyzstan, 19 January 2019. People believe that bathing in blessed waters during the holiday of Epiphany strengthens their spirit and body. (Photo by Igor Kovalenko/EPA/EFE)

Actors Jason Statham and Rosie Huntington-Whiteley arrive at the Metropolitan Museum of Art Costume Institute Gala (Met Gala) to celebrate the opening of “Manus x Machina: Fashion in an Age of Technology” in the Manhattan borough of New York, May 2, 2016. (Photo by Lucas Jackson/Reuters)

“Himalayan Dog”. This dog just appeared out of nowhere and followed us for an entire week during our trekking trip in the Himalayan outback. He always used to sleep in front of our tent and guarded us in the nights. When I decided to get up at 4 a.m. to climb the next 5000 m peak for sunrise he accompanied me as well. On the top he was sitting for the entire 30 minutes on this place looking straight into the countryside. Photo location: Ladakh, India. (Photo and caption by Sebastian Wahlhuetter/National Geographic Photo Contest)