Fireworks light the sky over Copacabana beach during New Year's Eve celebrations in Rio de Janeiro, Brazil, Thursday, January 1, 2016. (Photo by Mauro Pimentel/AP Photo)

Shi'ite fighters launch a rocket during clashes with Islamic State militants on the outskirts of al-Alam March 8, 2015. Thaier Al-Sudani: “It was me and a few other Iraqi journalists working for local outlets. We went to the frontlines in coordination with the Iraqi government forces and supporting militias. The press officer would come in the morning and take us to the frontline in a convoy. Whenever an area was won from Islamic State, the fighters would chant and pray and show victory signs. Most of the areas we were in didn't have residents, so after the battle they would resemble ghost towns; nothing but burnt cars and charred bodies of Islamic State fighters. Al-Alam was an exception as it had some residents who chanted for the government forces after their victory”. (Photo by Thaier Al-Sudani/Reuters)

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)

A preparatory model of the Imperial State Crown of India worn in 1911 by King George V stands next to original ledgers dating from 1735 in Garrard's flagship store in Mayfair on April 6, 2011 in London, England. Garrard is the world's oldest jewellers having been founded by George Wickes in 1735 and soon after appointed as goldsmith to the Prince of Wales. For over 160 years Garrard held the title of Crown Jeweller, bestowed by Queen Victoria in 1843, Garrard have served six successive monarchs. They have produced several royal crowns as well as the engagement ring presented to Kate Middleton by Prince William and formerly Princess Diana's engagement ring. (Photo by Oli Scarff/Getty Images)

A tired-looking Javan Fish Owl. (Photo by Fox Photos/Getty Images). 5th December 1973

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)