A child plays in front of “Etnias”, a large graffiti wall by Brazilian graffiti artist Eduardo Kobra created ahead of the Rio 2016 Olympic Games at Porto Maravilha in Rio de Janeiro, Brazil, 30 July 2016. The Olympics start on 05 August. Eduardo Kobra hopes to set a Guinness World Record for the largest graffiti created by a single artist. (Photo by Lukas Coch/EPA)

Kira Walkenhorst of Germany (L) signals as Doaa Elghobashy of Egypt (R) watches during the women's Beach Volleyball preliminary pool D game between Ludwig/Walkenhors of Germany and Elghobashy/Nada of Egypt the Rio 2016 Olympic Games at the Beach Volleyball Arena on Copacabana Beach in Rio de Janeiro, Brazil, 07 August 2016. (Photo by Antonio Lacerda/ANSA)

People walk along the Dune du Pilat (Dune of Pilat), the tallest sand dune in Europe, in La Teste de Buch, near Bordeaux, France, June 15, 2016. The dune has a volume of about 60,000,000 m³, measuring around 500 m wide from east to west and 2.7 km in length from north to south. Its height is currently 110 meters above sea level. (Photo by Sergio Perez/Reuters)

Prints of R$ 50 Brazilian reais bills sit on a table for inspection at at the Casa da Moeda, the national mint, in the Santa Cruz suburb of Rio de Janeiro, Brazil, on Tuesday, March 5, 2013. Brazil is likely to keep its key interest rate at a record low for the third straight meeting, as policy makers are caught between a fragile economic recovery and faster-than-expected inflation. (Photo by Dado Galdieri/Bloomberg)

“El rio mas bonito del Mundo”, the most beautiful river of the world, the “River of five colors”, the “Rainbow River”, or even the “Escaped from Paradise”, are the shimmering appellations that Colombians give to Cano Cristales, a small stream located in the heart of the Macarena National Park, 150 km (93 miles) south of Bogota. Photo: A waterfall is seen at the end of the rainy season, in August, when the water level finally decreases, in the Cano Cristales RIver in the Sierra de la Macarena in Colombia. It has become covered with a bright pink endemic aquatic plant, Macarenia Clavigera. (Photo by Olivier Grunewald)

A “Maya” girl sits in an altar during the traditional celebration of “Las Mayas” on the streets in Colmenar Viejo, near Madrid, Spain, Friday, May 2, 2014. The festivity of the Maya comes from pagan rites and dates from the medieval age, appearing in ancient documents, it takes place every year in the beginning of May and celebrates the beginning off the spring. A girl between 7 and 11years is chosen as “Maya” and should sit still, serious, and quiet for a couple of hours in an altar on the street decorated with flowers and plants, afterwards they walk to the church with their family where they attend a ceremony. (Photo by Daniel Ochoa de Olza/AP Photo)

A devotee with his body painted poses as he waits to perform during a ritual as part of the annual Shiva Gajan religious festival at Sona Palasi village, in West Bengal, India, April 11, 2016. Devotees offer sacrifices and perform acts of devotion during the festival in the hopes of winning the favour of Hindu god Shiva and ensuring the fulfillment of their wishes, and also to mark the end of the Bengali calendar year. (Photo by Rupak De Chowdhuri/Reuters)

A military guard carries flowers through the Cementerio Santa Ifigenia where the remains of former Cuban President Fidel Castro were entombed December 4, 2016 in Santiago de Cuba, Cuba. The tomb stands to the side of a memorial to the rebel soldiers killed in an attack that Castro led on Santiago's Moncada barracks on July 26, 1953, and in front of the mausoleum of Cuban national hero Jose Marti. (Photo by Chip Somodevilla/Getty Images)