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)

Karl Bang's paintings are unique because he combines totally different styles of painting within the same format. It is very difficult to design a balanced composition with realistic elements that are juxtaposed with flat colors and patterns. The faces of his subjects are painted realistically in the Western tradition with subtle gradations of color; while, his figures and costumes vignette into abstracted shapes, lines, flat colors and patterns that reflect Karl's background in China. It is as though there are different visual languages being spoken within his paintings.

Jewelry from packaging: Yoav Kotik’s rings, bracelets, necklaces and pendents are made from metal bottle caps. Yoav Kotik, the designer of "Precious metal" jewellery line, is a graduate of the "Bezalel academy of art and design" in Jerusalem. Yoav is a member of the Zik group. He frequently leads Master classes in the field of sculpture and design in recycled materials in academic institutes such as the "Shenkar academy of design" the "Bezalel academy" and the "Wizo academy". His works were presented in galleries across Israel, the UK, the Netherland and Japan.

A visitor looks at a Morris Mini-Minor Car on display at the Victoria and Albert museums' new major exhibition, “British Design 1948-2012: Innovation In The Modern Age” on March 28, 2012 in London, England. This car, which was designed by Alec Issigonis, was the first one off the production line. The exhibition showcases some of the most iconic product design, fashion, furniture, graphics, architecture and fine art from the last 60 years, and opens to the public from March 31, 2012. (Photo by Dan Kitwood/Getty Images)

French artist Thomas Lamadieu, also know as Roots Art, must really love looking at the sky. Every time he looks up, Thomas sees a potential canvas where the building rooftops frame the sky. He photographs it and uses the odd sky shapes to create whimsical line drawings. “My artistic aim is to show a different perception of urban architecture and the everyday environment around us, what we can construct with a boundless imagination,” says Thomas. (Photo by Thomas Lamadieu)

“Glenfinnan Viaduct is a railway viaduct on the West Highland Line in Glenfinnan, Lochaber, Highland, Scotland. It was built between 1897 and 1901. Located at the top of Loch Shiel in the West Highlands of Scotland, the viaduct overlooks the Glenfinnan Monument and the waters of Loch Shiel”. – Wikipedia

Photo: A view of the Glenfinnan Viaduct on March 30, 2012 in Glenfinnan, Scotland. Built by Sir Robert McAlpine, the single track viaduct that is made up of 21 arches is considered to have been one of the largest engineering projects of its time. Today, it is still used by ScotRail and was recently used for scenes in three of the Harry Potter films. (Photo by Jeff J. Mitchell/Getty Images)