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)

Chris Staring photographs a mysterious train graveyard in the heart of southern Bolivia, where the skeletons of British steam locomotives and rail cars rust away on the edge of the world’s largest salt flats. More than 100 rail cars and locomotives can be found in different states of decay in the train graveyard. (Photo by Chris Staring/Rex Features/Shutterstock)

US based toy inventor Steve Casino, 48, has spent almost two years turning peanut shells into these tiny figures. He has made almost 100 of the tiny four-inch statuettes to date- including well-known stars like Elton John and Johnny Depp. The intricate designs can often take up to 20 hours to create. Steve has even turned his unusual passion into a business, selling privately commissioned peanut statuettes as gifts and wedding cake toppers. (Photo by Steve Casino)

After the success of their Superman series in 2013, the Canadian Mint debuted a new set of coins honouring the Man of Steel at this year's Fan Expo in Toronto. The collection is made up of three silver coins worth $10, $15 and $20, and a gold coin worth $100. Photo: Close-up of the $10 silver coin in the new Superman series from the Royal Canadian Mint. (Photo by The Canadian Press)

A female street art collective has set a new Guinness World Record to create the largest spray-painted mural by multiple artists. Over 100 international female street artists came together to create the continuous mural in south London’s Leake Street Tunnel, made famous by Banksy, on March 8, 2014. The record was broken as part of all-female street art event Femme Fierce, the largest of its kind in the UK, which aims to celebrate women street artists across the world. Photo: Zabou's witty graffiti. (Photo by Dez Mighty/Susan Mackey)

(R-L) Jean-Jacques Cattier and his son Alexandre Cattier pose with the world largest bottle of Champagne “The Midas” by Armand de Brignac on April 6, 2011 in Berlin, Germany. The Midas is a massive 30-liter vessel and weights exactly 100 pounds. It's like having 40 pieces of the 750ml in one. Number one champagne brand in the world, Armand de Brignac is the luxury Champagne from the award-winning Champagne Cattier chateau of Chigny-les-Roses, France. (Photo by Andreas Rentz/Getty Images)

Canadian-Israeli film director Simcha Jacobovici holds two nails during a press conference on April 12, 2011. Jacobovici believes that the two nails discovered in a Jerusalem cave were used in the crucifixion of Jesus Christ. Jacobovici claims that the nails were tracked to an archeology laboratory in Tel Aviv, and though cannot be 100 per cent certain that they are the nails used in the crucifixion of Jesus, he claims if “you put two and two together and they seem to imply that these are the nails”. Experts at the Israel Antiquities Authority though cast doubt on Jacobovici's claims, and suggest that nails are commonly found in such locations. (Photo by Lior Mizrahi/Getty Images)

“La Tomatina is a festival that is held in the Valencian town of Buñol, in which participants throw tomatoes at each other”. – Wikipedia

Photo: A man sits in tomato pulp at the end of the world's biggest tomato fight at La Tomatina festival on August 26, 2009 in Bunol, Spain. More than 45000 people from all over the world descended on the small Valencian town to participate La Tomatina festival, with the local town hall estimating that over 100 tons of rotten and over-ripe tomatoes were thrown. (Photo by Jasper Juinen/Getty Images)