A woman prays at the edge of a river during a protest against the building of a pipeline near the Standing Rock Indian Reservation near Cannonball, North Dakota, U.S. November 2, 2016. (Photo by Stephanie Keith/Reuters)

Abbas (1944 – 25 April 2018) was an Iranian photographer known for his photojournalism in Biafra, Vietnam and South Africa in the 1970s, and for his extensive essays on religions in later years. He was a member of Sipa from 1971 to 1973, a member of Gamma from 1974 to 1980, and joined Magnum Photos in 1981. Here: Kuwait, 1991. (Photo by Abbas Attar/Magnum Photos)

A knife is seen beside a bowl containing blood after a ram was killed as a sacrifice in front of a shrine at the annual voodoo festival in Ouidah, Benin, January 10, 2016. In Ouidah, a small town and former slave port in the West African country of Benin, the annual voodoo festival gathers visitors from far and wide. It's a week that brings together priests and dignitaries, rich and poor, locals and visitors from as far afield as the Caribbean and France. The festival commemorates the estimated 60 million people who lost their homelands and their freedom during the African slave trade. (Photo by Akintunde Akinleye/Reuters)

Mask dancers take part in a parade during the the International Festival of Masquerade Games “Surva” in the town of Pernik, some 30 km from Sofia, Bulgaria, January 31, 2016. (Photo by Vassil Donev/EPA)

“Asaro from the Eastern Highlands”. The mudmen could not cover their faces with mud because the people of Papua New Guinea thought that the mud from the Asaro river was poisonous. So instead of covering their faces with this alleged poison, they made masks from pebbles that they heated and water from the waterfall, with unusual designs such as long or very short ears either going down to the chin or sticking up at the top, long joined eyebrows attached to the top of the ears, horns and sideways mouths. (Photo and caption by Jimmy Nelson)

Baka pygmies in their forest home preparing food in, Sangha Forest, Central African Republic, February 2016. Here, in their forest home, traditional life continues in the face of multiplying challenges ranging from poachers, to ill health. Deep in the rainforests of central Africa lives one of the world’s most mysterious tribes. (Photo by Susan Schulman/Barcroft Images)

A Taiwanese woman takes a photo of a Christmas tree decoration at a street in Taipei, Taiwan,13 December 2015. (Photo by Ritchie B. Tongo/EPA)