Photochromes are vibrant and nuanced prints hand-coloured from black-and-white negatives. Created using a process pioneered in the 1880s, these images offer a fascinating insight into the world when colour photography was still in its infancy. A Tour of the World in Photochromes is at the Swiss Camera Museum, Vevey, until 21 August. Here: Street food in the Strada del Porto in Naples, Italy, 1899. (Photo by Swiss Camera Museum/The Guardian)

A protester squirts a water gun at Catalan regional police in full riot gear during a protest over the eviction of squatters earlier in the week from “The Expropriated Bank”, in Barcelona, Spain, May 29, 2016. (Photo by Albert Gea/Reuters)

A girl looks at other children practicing on a boxing ring during an exercise session at a boxing school, in the Mare favela of Rio de Janeiro, Brazil, June 2, 2016. For many young residents the Luta Pela Paz (Fight For Peace) academy offers a glimpse of an alternative: a chance to build discipline and self-esteem through boxing and martial arts. (Photo by Nacho Doce/Reuters)

Two stags fight in a wildlife park in Aurach near Kitzbuehel, in the Austrian province of Tyrol. (Photo by Kerstin Joensson/Associated Press)

Pernille Ferdinandsen receives a neck tattoo from Peter Madsen during the third Copenhagen Ink Festival which opened Thursday May 9, 2013 in Copenhagen, Denmark, the biggest tattoo festival in Northern Europe. During the three days, 180 of the world's best and most celebrated national and international tattoo artists show the audience their skills in making art on the body and tattoo's on the audience. (Photo by Lars Krabbe/AP Photo)

A passenger plane comes into land over a field containing horses at Heathrow Airport on August 11, 2014 in London, England. Heathrow is the busiest airport in the United Kingdom and the third busiest in the world. The airport's operator BAA wants to build a third runway to cope with increased demand. (Photo by Peter Macdiarmid/Getty Images)

A boy runs past one of the exhibits during the Dinosaurs exhibition in Belgrade, Serbia, Thursday, August 21, 2014. “Dino Park” has opened at Belgrade's Kalemegdan Fortress. (Photo by Darko Vojinovic/AP Photo)