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)

Russian artist Salavat Fidai is obsessed with things in miniature, and he has previously painted miniatures on pumpkin seeds and carved sculptures into the graphite tips of pencils. For this project, he's gone for something a little bit bigger, but not by much. One of Fidai's favorite painters is the legendary Vincent Van Gogh, so he decided to do a series where he recreated some of Van Gogh's famous works on matchboxes.

The great vector artist OG Abel was a diamond in the rough. Growing up in violent surroundings, OG Abel found shelter in art. With an unsupportive father who always told him artist die broke, his only creative activity was strongly connected to religion. Having a church-going mother, OG Abel says he would spend hour drawing images from the Bible, his favorite pictures being those of animals, especially lions. He would also study the elaborate paintings in churches, the architecture, and/or the sculptures.

There is something frightening and at the same time appealing in the living sculptures of 27-year-old British artist Emma Fay. Body art in conjunction with the flexibility of acrobats and fantasy of the artist using water-based paints, a brush and sponge, is transformed into a beautiful work of art. It is not immediately possible to make out the human body in the picture. First you look at the landscape and suddenly begin to distinguish someone’s arm, or neck. Or you look into the eyes of an amazing bull, and it turns out that it is perfectly folded back. Lovely people, temples are and wonderful people-insects are.

In a remote location in rural America, a photographer has discovered a rather unique gathering: row after row of presidential busts. Like a zombie graveyard, the field contains 43 gigantic sculptures, ranging from Dick Nixon and FDR to JFK and Honest Abe. The likenesses weigh between 11,000 and 20,000 pounds, with some standing as tall as 20 feet. Almost all the busts are cracked, crumbling and worn by the elements, adding to their eerie appearance but not preventing the presidents from being recognizable at first glance. Here: Abraham Lincoln in front of presidential busts. (Photo by David Ogden/Caters News)

“These are the mind-bending sculptures that take up to 40 hours to create – as they're made entirely from pipe cleaners. The fuzzy flexible figures are made entirely from the tobacco cleaning tools – which are now more commonly found strewn across nurseries and art classrooms – to construct the incredible life-like animals”. – Caters News. Photo: New Pipe Cleaner Wolf. (Photo by Lauren Ryan)

These stunning light art pictures of skateboarding skeletons were created by Darren Pearson from Los Angeles. He works as a full time illustrator by day and by night he explores the varying landscapes of California in search of the perfect scene for his light-sculptures. Pearson makes complex light-effect photographs, none of which are photoshopped. He describes the work as location-based light art. Photo: A light skateboarder grinding a rail. (Photo by Darren Pearson/Caters News)