Children play in an outdoor shower as a soldier takes part in a surprise operation in the Manguinhos slum in Rio de Janeiro, Brazil, Thursday, January 18, 2018. Troops have been sent to Rio due to the increase of the violence, and in an attempt to help restore order, but so far have had little impact. The operation on Thursday took place three weeks ahead of Carnival, when thousands of tourists are expected to arrive in the city. (Photo by Leo Correa/AP Photo)

A traffic light is seen next to the Pink Supermoon in Frankfurt, Germany, April 8, 2020. (Photo by Kai Pfaffenbach/Reuters)

A girl holds up her hand to confront the police during a banned protest in Hong Kong on July 1, 2020. China imposed a controversial national security law on Hong Kong on Tuesday, a historic move that worried many Western governments that will strangle the finance hub's freedoms and hollow out its autonomy. (Photo by Keith Tsuji/Zuma Press/Rex Features/Shutterstock)

Camel herders scoop up water in plastic buckets from one of the few watering holes in the area, to water their animals near the drought-affected village of Bandarero, near Moyale town on the Ethiopian border, in northern Kenya, Friday, March 3, 2017. The U.N. humanitarian chief, Stephen O'Brien, toured Bandarero village on Friday and called on the international community to act to “avert the very worst of the effects of drought and to avert a famine to make sure we don't go from what is deep suffering to a catastrophe”. (Photo by Ben Curtis/AP Photo)

An Iraqi demonstrator runs as others burn tyres to cut-off roads in the southern city of Basra on November 25, 2019. (Photo by Hussein Faleh/AFP Photo)

Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

Voodoo pilgrims bathe in a waterfall believed to have purifying powers during the annual celebration in Saut d' Eau, Haiti, Saturday, July 16, 2016. Annually, the falls are the site of a large, important religious pilgrimage, during the festival of Our Lady of Carmel, from July 14–16. A Eucharistic rite is held during the festival, as well as various vodou rituals, but the penultimate devotional activity is bathing in the waters of the falls, and asking favors of the Virgin or Erzulie. After bathing, voodoo pilgrims throw away the dresses they wore to the site, and don new clothes for good luck. (Photo by Dieu Nalio Chery/AP Photo)

Attendees dressed as Poison Ivy and Harley Quinn arrive for opening day of the annual Comic-Con International in San Diego, California, United States July 21, 2016. (Photo by Mike Blake/Reuters)