Graffiti is painted on the bathroom walls at a restaurant in the Williamsburg area of Brooklyn borough in New York, United States, October 1, 2015. Some 2.4 billion people around the world don't have access to decent sanitation and more than a billion are forced to defecate in the open, risking disease and other dangers, according to the United Nations. To mark World Toilet Day on November 19, Reuters photographers captured pictures of toilets in cities, towns and villages around the globe. (Photo by Shannon Stapleton/Reuters)

Underwater photographer Alexander Semenovs has snapped some of the most stunning, fragile life forms anywhere on planet Earth. Shot in deep, dark conditions, the images continue to provide an insight into what lies beneath, with glowing creatures appearing a lot like aliens in the pitch-black water. Semenovs has shot the likes of bioluminescent jellyfish, aggressive-looking worms and many species that leave a lot to the imagination. The 30-year-old from Moscow does the majority of his work in the White Sea, near the Arctic Circle. Here: A Comb jelly – Beroe cucumis. (Photo by Alexander Semenovs/Caters News)

The Spanish photographer Xavi Bou digitally combines sequential pictures of birds to create a single image, or chronophotograph, that reveals the shapes of their flight paths against Catalonian skies. His work shows the variety and beauty to be found in the daily activities of the local birds, including spiralling storks, swooping starlings and giddy swifts. Here: European herring gulls at Llobregat Delta. (Photo by Xavi Bou/Rex Features/Shutterstock)

Afghanistan, published by Taschen later July, is a retrospective portfolio of the Magnum photographer Steve McCurry’s most striking images of the country, from 1979 to 2016. Here: Kunar province, 1980. Armed mujahideen carry animal skins to use as inflatable buoys to cross rapids. (Photo by Steve McCurry/Taschen/Magnum Photos/The Guardian)

As an American in 1990s Cuba, Tria Giovan risked being branded a traitor. But the photographer continued to visit and, from the dance hall to the hair salon, she captured the resilient spirit of the Cuban people. The 120 images in Tria Giovan’s “The Cuba Archive” are from the period in the 90s when, as an American, travel to Cuba could have seen her branded a traitor, as the country was subject to a US trade embargo. Her trip required lots of planning – and patience. (Photo by Tria Giovan/The Guardian)

This 1950s photo provided by the Estate of Vivian Maier and John Maloof Collection shows Maier in a self-portrait as she looks into a storefront wearing a hat in New York. New research about Maier shows the enigmatic Chicago nanny was obsessive about honing her skills as a photographer starting in 1950. (Photo by Vivian Maier/Estate of Vivian Maier and John Maloof Collection via AP Photo)

Penguins majestically march on sand before heading out for a morning swim. Wildlife photographer Wim van den Heever, 45, visited the Falkland Islands this year to shoot pictures and scout the area for future tours. Wim’s breathtaking images show a small group of king penguins before they head out to sea at sunrise. Here: King Penguins marching during sunrise, Falkland Islands. (Photo by Wim van den Heever/Caters News)

These hilarious images show dogs enjoying a day out exploring New York’s most iconic tourist hotspots Photographer Mark McQueen captured the canines hanging out near landmarks like the Brooklyn Bridge, on 5th Avenue and Times Square. Here: Take my picture! Apartment dogs in the East Village are always happy to be out for a walk. (Photo by Mark McQueen/Caters News Agency)