A Mai-Mai rebel soldier shows off his guns at a checkpoint near the Mugunga refugee camp in Zaire; 1996. (Photo by Carol Guzy/The Washington Post)

In this June 20, 2015 photo, Niberta Galvez uses the bottom half of his shirt to collect coca leaves in Samugari, Peru. Coca farmers were among the locals who, in 1984, formed citizen militias to help the military beat back Shining Path rebels, reducing them to a small group of fewer than 500 who now are deeply involved in drug trafficking. (Photo by Rodrigo Abd/AP Photo)

In this June 23, 2015 photo, Ashaninka Indian beauty contestants pose for a photo with members of a visiting music group, hired to perform during the annual founding anniversary festivities, in Otari Nativo, Pichari, Peru. The contestants wear the simple brown dresses of the Ashaninka woman, their faces dotted in a traditional design with a red dye extracted from a spice called achiote. (Photo by Rodrigo Abd/AP Photo)

A sauna building sits above the clouds at 9,280 feet (2,752 meters) at the Rifugio Lagazuoi in the Dolomite Mountains near Cortina d' Ampezzo in northern Italy July 17, 2015. The Dolomites are home to the Dolomiti Bellunesi National Park and were declared a UNESCO World Heritage Site in August, 2009. (Photo by Bob Strong/Reuters)

Afghan girl athletes perform Wushu on the top of a hill in Kabul, capital of Afghanistan, January 18, 2017. In the conservative Afghan society where people especially in the countryside deeply believe in the old traditions and don't allow their girls and female members of the family to go out of home, exercising sport in open is extremely risky, but a group of girls are broken the taboo and exercising Wushu on a hilltop where the temperature is minus 2 Celsius degrees. (Photo by Rahmat Alizadah/Xinhua/Barcroft Images)

People and sea-gulls bathe in the sea as the sun goes up with red colors in Stralsund close to the baltic sea island of Rügen, on early November 23, 2016. (Photo by Stefan Sauer/AFP Photo/DPA)

Indian women dressed in traditional attire drive motorcycles as they take part in a procession celebrating “Gudhi Padwa” or the Maharashtrian New Year in Mumbai on March 28, 2017. Gudhi Padwa is the Hindu New Year for people in India's Maharashtra state and marks the end of a harvest and the beginning of a new one. (Photo by Punit Paranjpe/AFP Photo)

A group of colorful row houses are reflected on to the top of a black car parked on 3600 block of N street in the Georgetown section of Washington DC, February 16, 2017. (Photo by John McDonnell/The Washington Post)