A spotless GWR (Great Western Railway) locomotive, the “Royal Sovereign” waiting to carry Queen Victoria's coffin. (Photo by Hulton Archive/Getty Images). 28th January 1901

A Viet Cong suspect holds his hands up after a Vietnamese Ranger from the 21st Vietnam Infantry Division routed him from his hiding place. (Photo by Keystone/Getty Images). 7th November 1967

A woman carries her child, both wearing traditional red clothes celebrating the Chinese Lunar New Year in Bangkok February 19, 2015. (Photo by Damir Sagolj/Reuters)

A Tibetan man stirs butter tea made for the arriving guest during the function organised to mark Losar or the Tibetan New Year at a Tibetan Refugee Camp in Lalitpur February 19, 2015. Tibetans across the world marked the arrival of the New Year with prayers and festivities. (Photo by Niranjan Shrestha/AP Photo)

American students going wild during their Spring Break week-long recess in Cancun, Mexico on March 10, 2007. (Photo by Keystone USA/ZUMA Press/Rex Features/Shutterstock)

Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)

An Indian woman wrapped in a shawl travels with others on a bullock cart on a cold day at Jhansi district, in Bundelkhand, India, Monday, December 29, 2014. Most parts of north India Monday continued to shiver under biting cold with the mercury dipping several notches. (Photo by Rajesh Kumar Singh/AP Photo)

Tibetan men get ready to perform a traditional dance during a special prayer ceremony on the third day of the Tibetan New Year celebrations in Kathmandu, Nepal, Wednesday, March 1, 2017. Tibetans follow this ritual called “sangtsol” to ask for good luck in the new year. (Photo by Niranjan Shrestha/AP Photo)