Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

An aerial view shows the Amazon rainforest at the Bom Futuro National Forest near Rio Pardo in Porto Velho, Rondonia State, Brazil, September 3, 2015. The town of Rio Pardo, a settlement of about 4,000 people in the Amazon rainforest, rises where only jungle stood less than a quarter of a century ago. Loggers first cleared the forest followed by ranchers and farmers, then small merchants and prospectors. Brazil's government has stated a goal of eliminating illegal deforestation, but enforcing the law in remote corners like Rio Pardo is far from easy. (Photo by Nacho Doce/Reuters)

South African Sangomas are wizards and witches who are supposedly chosen by their ancestors to follow a traditional training and go through a rite of passage after which they become Sangomas and can cure and help people. They are so respected and trusted that western medical authorities have actually advised the government of South Africa to develop its cooperation with Sangomas in order to improve hygiene and health among the population. (Photo by Patrick Durand/Sygma via Getty Images)

The Niterói Contemporary Art Museum (Museu de Arte Contemporânea de Niterói — MAC) is situated in the city of Niterói, Rio de Janeiro, Brazil, and is one of the city’s main landmarks. It was completed in 1996.

Inflatable dolls in the shape of ducks are seen in front of the National Congress during a protest against tax increases in Brasilia, Brazil, March 29, 2016. The campaign “I will not pay the Duck” is organized by the Federation of Industries of Sao Paulo (FIESP) and uses the duck symbol in reference to industries that pay high taxes. (Photo by Gregg Newton/Reuters)

A worker manually changes the direction of the bonde, the typical tram line in Santa Teresa neighborhood, using a rope in Rio de Janeiro, Brazil, September 9, 2015. The Santa Teresa bonde, called “Bondinho” in Portuguese, is running with passengers as a part of a test period, after the service was suspended in 2011 following an accident that killed six people, according to residents. (Photo by Pilar Olivares/Reuters)

A woman looks for fruits to buy inside a bus called Sacolao in Santa Teresa neighborhood in Rio de Janeiro, Brazil, July 7, 2015. The bus, which began operating as a municipal initiative but has been taken over by a private enterprise, arrives every week in some neighborhoods to facilitate families with their grocery shopping and sells food at an affordable price, according to sellers. (Photo by Pilar Olivares/Reuters)

A trainer tries to convince a dog to jump over an obstacle during the Dog Olympic Games in Rio de Janeiro, Brazil, Sunday, September 18, 2016. Owner of the dog park and organizer of the animal event Marco Antonio Toto says his goal is to socialize humans and their pets while celebrating sports. (Photo by Silvia Izquierdo/AP Photo)