A staff member of Sony Computer Entertainment tries out PlayStation 4's virtual reality headset Project Morpheus at its booth in Tokyo Game Show 2014 in Makuhari, east of Tokyo September 18, 2014. (Photo by Yuya Shino/Reuters)

A worshipper wearing a kerchief with the image of the Our Lady of Fatima attends a mass at the Our Lady of Fatima shrine, in Fatima, central Portugal, Wednesday, May 13, 2015. Every year on May 12 and 13 tens of thousands of Catholic believers go on pilgrimage to the Fatima sanctuary to pray and attend masses where the apparitions of the Virgin Mary were witnessed by three shepherd children Lucia, Jacinta and Francisco in 1917. (Photo by Francisco Seco/AP Photo)

Part made cricket bats sit in a box at the Salix Cricket Bat Company in Langley, Britain July 6, 2015. Salix Cricket Bat Company use traditional tools and techniques to make cricket bats by hand. (Photo by Neil Hall/Reuters)

Men soar through the air on a wooden sledge during a traditional Bavarian horn sledge race, known as “Schnablerrennen”, in Gaissach near Bad Toelz, Germany, January 22, 2017. (Photo by Michael Dalder/Reuters)

(L-R) Marisa Berenson, Caroline de Maigret, Nicki Minaj and Lou Doillon attend the Haider Ackermann show as part of the Paris Fashion Week Womenswear Fall/Winter 2017/2018 on March 4, 2017 in Paris, France. (Photo by Bertrand Rindoff Petroff/Getty Images)

Pilgrims lift up their dresses as they cross the Quema river during the annual El Rocio pilgrimage in Villamanrique, near Sevilla on June 1, 2017. El Rocio pilgrimage is the largest in Spain with hundreds of thousands of devotees wearing traditional outfits converging in a burst of colour as they make their way on horseback and decorated carriages across the Andalusian countryside. (Photo by Cristina Quicler/AFP Photo)

A man arranges a display of cacti during preparations for the RHS Chelsea Flower Show in London, Britain May 21, 2016. (Photo by Neil Hall/Reuters)

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)