Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

Competitors take part in the 8th annual World Gravy Wrestling Championships at the Rose n Bowl Pub in Bacup, north west England on August 31, 2015. Contestants must participate in fancy dress and wrestle in a pool of Lancashire Gravy for 2 minutes whilst being scored for a variety of wrestling moves. (Photo by Oli Scarff/AFP Photo)

A picture made available on 13 May 2016 shows A Tiwa girl performing her traditional dance as they celebrated the Wanchuwa festival in Karbi Anglong District of Assam state, India, 11 May 2016. Wanchuwa is one of the most important festivals of the Tiwa tribal community living in the hills as it is related with agriculture which is the mainstay of their economy. Tiwas pray for a bountiful harvest during this festival and to protect their crops from pest and other natural calamities. Tiwa is a major tribe of Assam state who practice Jhum or shifting cultivation for their living in the hills. (Photo by EPA/Stringer)

A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

Newborn giant panda triplets, which were born to giant panda Juxiao (not pictured), are seen inside an incubator at the Chimelong Safari Park in Guangzhou, Guangdong province August 9, 2014. According to local media, this is the fourth set of giant panda triplets born with the help of artificial insemination procedures in China, and the birth is seen as a miracle due to the low reproduction rate of giant pandas. (Photo by Reuters/China Daily)

A tale of two foxes. Surprising behaviour, witnessed in Wapusk national park, on Hudson Bay, Canada, in early winter. Red foxes don’t actively hunt Arctic foxes, but where the ranges of two predators overlap, there can be conflict. Though the light was poor, the snow-covered tundra provided the backdrop for the moment that the red fox paused with the smaller fox in its mouth in a grim pose. (Photo by Don Gutoski/2015 Wildlife Photographer of the Year)

Born in 1958 in Abbazia, Italy, Frank Horvat is considered one of the founding fathers of French fashion photography. Frank Horvat: Storia di un Fotografo is on at Palazzo Chiablese Musei Reali, Turin, until 16 June. Here: Prostitutes, Bois de Boulogne, 1956. (Photo by Frank Horvat/The Guardian)

A colony of penguins gather with the Bark Europa in the background, on March 05, 2015 in South Georgia Island. An adventurer has documented his 5,000 miles journey aboard a 100-year-old ship, sailing from Argentina to Antarctica to Cape Town. (Photo by Andrew Orr/Barcroft Images)