A woman walk by South Korean police during a anti-terror exercise on March 9, 2012 in Seoul, South Korea. The drill is part of South Korea's preparation for the upcoming 2012 Seoul Nuclear Security Summit, scheduled for March 26 and 27. Some 50 world leaders, including U.S. President Barack Obama, are expected to attend the summit to discuss how to make the world safe without nuclear weapons. (Photo by Chung Sung-Jun/Getty Images)

Nurse's Home, North Brother Island, New York. Photographer Christopher Payne specializes in the documentation of America’s vanishing architecture and industrial landscape. His new book, North Brother Island: The Last Unknown Place in New York City, explores an uninhabited island of ruins in the East River of New York City. (Photo by Christopher Payne)

Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

In this May 24, 2016 photo, a young boy descends the Qullqip'unqu mountain looking out at the tens of thousands of pilgrims gathered to celebrate the three-day festival Qoyllur Rit’i, translated from the Quechua language as Snow Star, in the Andean Sinakara Valley, in Peru's Cusco region. The celebration that mixes Catholic and indigenous beliefs honors Jesus as well as the area’s glacier, which is considered sacred among some indigenous people. While the native celebration is far older, the Christian part of the ritual stretches back to the 1700s, when Jesus is said to have appeared to a young shepherd in the form of another boy. (Photo by Rodrigo Abd/AP Photo)

Duncan Fenton from the Society of William Wallace stands next to a 700-year-old letter believed to have been in the possession of William Wallace, which has returned to National Records of Scotland on January 12, 2012 in Edinburgh, Scotland. (Photo by Jeff J. Mitchell/Getty Images)

A super flexible schoolboy has become a limbo legend - by roller-skating under 39 cars in a row. It took six-year-old Gagan Satish just 29 seconds to cover a distance of nearly 70 metres with his face just five inches from the ground. (Photo by Arkaprava Ghosh/Barcroft Media India)

Ten-year-old panda Xin Yue channels Kate Winslet in Titantic at Taihu Lake National Wetland Park in the Jiangsu Province of China.