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)

Founded in 1989, the Icehotel in Swedish Lapland is built from the snow up each year, using ice from the local river. The rooms are designed by international artists and this year feature spacemen and an ice queen. The hotel has 35 suites, featuring ice carvings designed by 36 different artists from 17 countries. (Photo by Asaf Kliger/IceHotel/The Guardian)

Swedish photographer Paul Hansen won the 2012 World Press Photo award Friday for newspaper Dagens Nyheter with a picture of two Palestinian children killed in an Israeli missile strike being carried to their funeral.

Photo: In this photo provided on Friday February 15, 2013 by World Press Photo, the 2013 World Press Photo of the year by Paul Hansen, Sweden, for Dagens Nyheter, shows two-year-old Suhaib Hijazi and her three-year-old brother Muhammad who were killed when their house was destroyed by an Israeli missile strike. Their father, Fouad, was also killed and their mother was put in intensive care. Fouad's brothers carry his children to the mosque for the burial ceremony as his body is carried behind on a stretcher in Gaza City, Palestinian Territories, November 20, 2012. (Photo by Paul Hansen/Dagens Nyheter/AP Photo)

A couple sunbath on the beach in Ostrowo, northern Poland, July 20, 2015. Picture taken July 20, 2015. (Photo by Kacper Pempel/Reuters)

Host Jennifer Lopez performs during the 2015 American Music Awards in Los Angeles, California November 22, 2015. (Photo by Mario Anzuoni/Reuters)

Dancers rehearse for the Rockettes 2015 Radio City Christmas Spectacular in New York October 15, 2015. (Photo by Lucas Jackson/Reuters)

Singer Zendaya arrives at the 2015 American Music Awards in Los Angeles, California November 22, 2015. (Photo by David McNew/Reuters)

A model presents a creation by Maltese hairstylist Marielle Calleja of Prive at the Malta Fashion Awards 2015 at the Marsa Shipbuilding warehouse in Marsa, outside Valletta in Malta, May 16, 2015. (Photo by Darrin Zammit Lupi/Reuters)