People in boats approach “Die Badende” (“The Bather”), a giant sculpture showing a woman's head and knees as if she were resting in the Binnenalster lake on August 3, 2011 in Hamburg, Germany. The sculpture, which is made of styrofoam and steel and measures 4 meters high and 30 meters long, is a project by artist Oliver Voss and will be on display for the next ten days. (Photo by Sean Gallup/Getty Images)

Volunteer rescuers prepare to drag a beached humpback calf to sea at Surfers Paradise Beach on August 8, 2011 on the Gold Coast, Australia. The humpback calf was stranded on the beach yesterday for hours before volunteer rescuers were able to drag it back to the sea. SeaWorld Australia says a mother and calf humpback were sighted near where the calf was released and are hoping to get photos to verify it is the same calf and that it has been reunited with it's mother. (Photo by 2011 SeaWorld Australia via Getty Images)

Photochromes are vibrant and nuanced prints hand-coloured from black-and-white negatives. Created using a process pioneered in the 1880s, these images offer a fascinating insight into the world when colour photography was still in its infancy. A Tour of the World in Photochromes is at the Swiss Camera Museum, Vevey, until 21 August. Here: Street food in the Strada del Porto in Naples, Italy, 1899. (Photo by Swiss Camera Museum/The Guardian)

This photo taken on August 7, 2016 shows mahjong enthusiasts playing mahjong under water in a swimming pool at a diving club in the Chinese city of Chongqing. Only participants with proper diving certification were allowed to take part in the underwater competition. (Photo by AFP Photo/Stringer)

In this April 4, 2014 file photo, a community policeman kicks a man who they alledge participated in an ambush against them near the town of La Concepcion, Mexico. The vigilante force was set-up by affected communities opposed to the construction of the La Parota hydroelectric dam. Two vigilantes were injured and one died. (Photo by Bernandino Hernandez/AP Photo)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

Farmers clash with riot policemen during a protest outside the Greek Agriculture Ministry on March 8, 2017 in Athens, Greece. Two people were detained after the windows of two police vans were smashed as approximately 1,000 farmers, mainly from the island of Crete, took part in the protest. (Photo by Nikolas Georgiou/ZUMA Wire/Rex Features/Shutterstock)

Cosplay fans (R) take selfies as comic book and gaming fans attend the annual Ani-Com and Games Fair in Hong Kong on July 28, 2017. Tens of thousands were expected to attend the annual event on animation, comics and games, from July 28 to August 1. (Photo by Isaac Lawrence/AFP Photo)