“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)

In this July 23, 2013 photo, sand fills an abandoned house in Kolmanskop, Namibia. Kolmanskop, was a diamond mining town south of Namibia, build in 1908 and deserted in 1956. SInce then, the desert slowly reclaims its territory, with sand invading the buildings where 350 German colonists and more than 800 local workers lived during its hay-days of the 1920s. (Photo by Jerome Delay/AP Photo)

A three-month-old Sumatran tiger cub named “Bandar” shows his displeasure after being dunked in the tiger exhibit moat for a swim reliability test at the National Zoo in Washington, on November 6, 2013. All cubs born at the zoo must take a swim test before being allowed to roam in the exhibit. Bandar passed his test. (Photo by Manuel Balce Ceneta/Associated Press)

Sarah Paulson and Amanda Peet arrive at the 20th annual Screen Actors Guild Awards. (Photo by Jordan Strauss/AP Photo/Invision)

Three very colouful alpacas enjoy the hot weather at Toft Farm, Rugby, on July 19, 2013. (Photo by Caters News)

A sеx worker participates in a march to raise public awareness on human rights issues in their profession on International Day to End Violence Against Sеx Workers in Skopje, Macedonia December 17, 2016. (Photo by Ognen Teofilovski/Reuters)

VIETNAM: A Vietnamese woman, wearing the traditional “ao dai” long dress, poses for photos along peach blossom flowers ahead of the Vietnamese “Tet” (Lunar New Year festival), in a field in Hanoi, Vietnam, February 2, 2016. (Photo by Reuters/Kham)

A “creuseur”, or digger, a plastic lantern on his head, readies to enter a copper and cobalt mine in Kawama, Democratic Republic of Congo on June 8, 2016. Cobalt is used in the batteries for electric cars and mobile phones. Working conditions are dangerous, often with no safety equipment or structural support for the tunnels. The diggers say they are paid on average US$2-3/day. (Photo by Michael Robinson Chavez/The Washington Post)