Men look on from the banks of Rio Doce (Doce River), which was flooded with mud after a dam owned by Vale SA and BHP Billiton Ltd burst, as the river joins the sea on the coast of Espirito Santo in Regencia Village, Brazil, November 22, 2015. (Photo by Ricardo Moraes/Reuters)

People dressed in costumes have a break while marching during the Vijanera Festival, in the small village of Silio, northern Spain, Sunday, January 3, 2016. The Vijanera masquerade, of pre-Roman origin, is the first carnival of the year in Europe symbolizing the triumph of good over evil and involving the participation of crowds of residents wearing different masks, animal skins and brightly coloured clothing with its own complex function and symbolism and becoming the living example of the survival of archaic cults to nature. (Photo by Francisco Seco/AP Photo)

A child lies in a puddle of coloured water during “Huranga” at Dauji temple near the northern Indian city of Mathura, March 7, 2015. “Huranga” is a game played between men and women a day after Holi, the festival of colours, during which men drench women with liquid colours and women tear off the clothes of the men. (Photo by Anindito Mukherjee/Reuters)

At the beginning of the 20th century, Edward S. Curtis set out to document what he saw as a disappearing race: the Native American. From 1907 to 1930, Curtis took more than 2,000 photos of 80 tribes stretching from the Great Plains to the Pacific Northwest and Alaska. He then published and sold these photos, along with narrative text, in 20 volumes of work known as “The North American Indian”. It is one of the most significant collections of its kind, “probably the most important photographic document of its age and its topic,” said Jeffrey Garrett, associate university librarian for Special Libraries at Northwestern University. (Photo by Edward S. Curtis)

Burger King employee Rumi Sekine shows the Kuro Diamond burger, right, and the Kuro Pearl burger at its Shibuya restaurant in Tokyo Tuesday, September 16, 2014. The international hamburger chain in Japan will launch the two new “kuro burger”, or “black burger” menus that sport buns, cheese and sauce all in black color, starting on Friday, Sept. 19, for a limited period. The buns and cheese are darkened with bamboo charcoal while the beef patties made with black-pepper are topped with the garlic sauce using squid ink. (Photo by Koji Sasahara/AP Photo)

Jan Kara (R) and Jan Holan pedal their boat, made with plastic bottles, on the Elbe river near Kostelec nad Labem July 15, 2014. Jan Kara, a 22-year-old student, and Jakub Bures, a 22-year-old car mechanic, built the 10-metre (32.8-feet) long boat from 5000 plastic bottles strapped to a wooden frame. (Photo by David W. Cerny/Reuters)

Romanian soldiers take part in a joint military exercise with NATO members, called “Agile Spirit 2015” at the Vaziani military base outside Tbilisi, Georgia, July 21, 2015. Georgian soldiers along with U.S. marines and platoon-size units from Bulgaria, Latvia, Lithuania and Romania are taking part in the exercises at the Vaziani military base outside Tbilisi. (Photo by David Mdzinarishvili/Reuters)

A hand of a labourer pushes bricks at a traditional brick factory in Arab Mesad district of Helwan, northeast of Cairo, May 14, 2015. About 45 labourers are employed at the brick factory and most work 10 hours a day. Adult workers earn a daily wage of 70 Egyptian pounds ($9) and child workers earn 40 Egyptian pounds ($5). The labourers, who are usually temporary or seasonally employed in Egypt's brick-making industry, experience unsafe work conditions, according to local media. (Photo by Amr Abdallah Dalsh/Reuters)