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)

Talk-show host Oprah Winfrey interviewing cyclist Lance Armstrong during taping for the show "Oprah and Lance Armstrong: The Worldwide Exclusive" in Austin, Texas. The two-part episode of "Oprah's Next Chapter" will air nationally Thursday and Friday, Jan. 17-18, 2013. (AP Photo/Courtesy of Harpo Studios, Inc., George Burns)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

A frightened maid, played by Phoebe Hodgson, knocks a bust off a tall pedestal while dusting, in a scene from the play “Queen High” at the Queen's Theatre. (Photo by Sasha/Getty Images). 1926

Mechanic and welder Sergei Kulagin, 32, strengthens the bracing of a spider sculpture, made by Kulagin, during a demonstration on the wall of an automobile repair workshop in the town of Divnogorsk outside Krasnoyarsk, Siberia, October 15, 2014. Enthusiast Kulagin, who works as a mechanic of an automobile service station, created about 20 sculptures made of used car parts and components during his non-working hours. (Photo by Ilya Naymushin/Reuters)

This diver almost got sucked into the mouth of a massive whale shark as it feeds on plankton. But far from staring into the jaws of death – the shark, which are the sea's largest fish, is actually vegetarian. The relieved diver escaped from the encounter unscathed and continued to enjoy the presence of the incredibly docile animals. The stunning photograph, by Mauricio Handler, was taken during a feeding session where more than 600 of the huge creatures gathered to feed on tuna spawn. (Photo by Mauricio Handler/Daily Mail/Solent)

In this Friday, March 28, 2014 photo, singers of the Moranbong Band, Jong Su Hyang, foreground, and Pak Mi Kyong, left perform on their stage in Pyongyang, North Korea. Step aside, Sea of Blood Opera. North Korean leader Kim Jong Un's favorite guitar-slinging, miniskirt-sporting girl group, the Moranbong Band, is back. And these ladies know how to shimmy. (Photo by Jon Chol Jin/AP Photo)

Pierre Gonnord started by photographing his neighborhood but soon left France for Spain, where he lives since 1988. Italy, Portugal, Japan, United States are just some of the countries where Pierre Gonnord has gone in search of models.