Britain's Red Arrows airplane display team perform during D-Day commemorations in Portsmouth in southern England on June 5, 2014. Several hundred surviving veterans of the 1944 D-Day landings are commemorating the 70th anniversary of the mission on both sides of the English channel. (Photo by Carl Court/AFP Photo)

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 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)

A villager run as Mount Sinabung erupt at Sigarang-Garang village in Karo district, Indonesia's North Sumatra province, February 1, 2014. Four people died and more than 28, 000 villagers have been evacuated since authorities raised the alert status for the volcano to the highest level in November 2013, local media reported on Saturday. (Photo by Reuters/Stringer)

A preparatory model of the Imperial State Crown of India worn in 1911 by King George V stands next to original ledgers dating from 1735 in Garrard's flagship store in Mayfair on April 6, 2011 in London, England. Garrard is the world's oldest jewellers having been founded by George Wickes in 1735 and soon after appointed as goldsmith to the Prince of Wales. For over 160 years Garrard held the title of Crown Jeweller, bestowed by Queen Victoria in 1843, Garrard have served six successive monarchs. They have produced several royal crowns as well as the engagement ring presented to Kate Middleton by Prince William and formerly Princess Diana's engagement ring. (Photo by Oli Scarff/Getty Images)

A tired-looking Javan Fish Owl. (Photo by Fox Photos/Getty Images). 5th December 1973

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)

Fog hangs between pine trees in a forest near Neubrueck, eastern Germany, on November 20, 2012. Meteorologists forecast cloudy sky and temperatures around 5 degrees Celsius for the region. (Photo by Patrick Pleul/AFP Photo)