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)

A spooky sight to behold! This is what a psychiatric hospital that has been abandoned for years looks like. Complete with bowling alley and a theater, the hospital shows just how much nature has weathered it over time as paint peels from the walls and the mattress gather dust. Here: This area of the hospital was last used as a day care center in the early 2000s. (Photo by Will Ellis/Caters News)

My name is Chris Kapono and I am a self-taught artist living in Missouri. I have been drawing and painting ever since I can remember and art has been a big part of my life. My love of animals and nature is reflected in my art and sometimes interesting things I find on walks in the woods will find their way into some of my pieces!

The ‘Stop the Violence’ advertising campaign by Brazilian agency Terremoto Propaganda aims to reduce the risk of accidents on the road. The visually grabbing print campaign shows a vehicle painted on the face of one person and the fist of another, drawing the comparison between what is widely known to be intentional violence, such as punching someone in the face, with what many incorrectly consider unintentional, like speeding or unsafe lane changes. Let us know what you think about this campaign in the comments below.

When Roberto Perez (also known as Rob The Original) gives you a haircut, it’s probably not going to be just a haircut. This San-Antonio-based artist and hair stylist creates amazing works of art using nothing but his clients’ scalp and hair as his canvas. Perez can create just about anything he or his clients can think of – from a photo-realistic portrait or illustration to full-head paintings or graphic designs.

The photos, created by Tito Mouraz in Portugal, look too surreal, and it takes a while to realize that these are actually not painting but reality. The way people can completely transform the terrain is very reminiscent of the way people tend to change themselves. Chip away the granite of their soul, turning it into something that fits their idea of perfection. However, in the end, most of them end up with an obscene parody of beauty, rather than something truly marvelous. The reason for it is probably that people are actually oblivious to the true image of beauty, making them stumble around in the dark, hoping to find something that might not exist at all. (Photo by Tito Mouraz)

A British couple drink hot chocolate at Chillout cafe in Dubai May 12, 2013. Chillout, owned by UAE's Sharaf Group, is the first ice lounge in the Middle East, with temperatures set at –6 degrees Celsius (21 degrees Farenheit). The cafe, with its illuminated interiors, curtains, paintings and seating arrangements, is all made of carved ice and frozen sculptures. (Photo by Ahmed Jadallah/Reuters)

Do you ever get the irresistible urge to light matches on fire, especially if there are many of them in one place? If you do, you shouldn’t come near the giant globe made by an American artist Andy Yoder. The thing is, this 42” globe is made entirely out of matches on the outside, while the center was made using plywood, foam, and cardboard. It took Andy two years to complete his work, finally finishing in 2014. Each of the matches used was hand-painted and then glued in place. Also, in order to prevent his masterpiece from catching fire, Andy Yoder has doused his work with a flame repellant.