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)

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!

For centuries the Highlands peoples of Papua New Guinea fought over land, women and pigs. Sorcery and battle skills could elevate a clan to Bigmanship, where the bigger the “presentation”, the bigger the man. Clans therefore would paint their bodies and create fearsome masks as part of their psy. Here: These are the terrifying tribe of “mudmen” from a remote part of Papua New Guinea. (Photo by Jeremy Hunter/Exclusivepix Media)

The world's biggest copy of the Mona Lisa is unveiled on October 28, 2009 in Wrexham, Wales The giant version of Leonardo da Vinci's masterpiece measures 17.5 metres across and is 50 times bigger than the original painting and was created by community groups in Wrexham and artist Katy Webster. (Photo by Christopher Furlong/Getty Images)

Paintings are moved on a stand at the “London Art Fair” on January 18, 2012 in London, England. The fair includes over 100 different stands featuring work by well known 20th century British artists and showcases some of the best emerging talent in the art world today. The show runs until January 23, at Business Design Centre in Islington. (Photo by Dan Kitwood/Getty Images)

Das Park Hotel was designed by Austrian architect and designer Andreas Strauss , and it is located in Linz, Austria. From inside, “rooms” have been humanized by Austrian artist Thomas Latzel Ochoa, who painted illustrations on walls. Hotel is open from May till October.

Sarel Theron is a freelance digital matte painter and concept artist from Cape Town, South Africa. Theron has worked on numerous projects for local and international clients, including book cover illustrations, matte paintings for commercials, concept art for various pitches, and tutorials for digital art magazines.

Central to The Capture Site on the R103 in the KwaZulu-Natal Midlands – where Nelson Mandela was arrested in 1963 – is a sculptural installation by Johannesburg artist Marco Cianfanelli. When viewed from a distance, the 50 painted laser-cut steel columns form the image of Madiba’s face. Click on the image below for more on The Capture Site.