A dump truck carrying cleaning workers drives on Havana's malecon as a wave crashes on the sea wall, in Cuba, Tuesday, January 24, 2017. Due to high winds and tides, the sea pushed over the sea wall, flooding low parts of the Vedado neighborhood of Havana. (Photo by Desmond Boylan/AP Photo)

Undated handout photo of members of Ballet Ireland during a photocall on Edinburgh's Calton Hill before taking part in the Edinburgh Festival 2018 in Edinburgh, Scotland. Issue date: Tuesday, August 7, 2018. (Photo by Julie Howden/Culture Ireland/PA Wire)

Volunteers throw a mixture of water, neem herb and turmeric as an alleged natural disinfectant on a street in a residential area during a government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus, in Chennai on April 7, 2020. (Photo by Arun Sankar/AFP Photo)

Peng Jing, 24, attends her wedding photography shoot after the lockdown was lifted in Wuhan, capital of Hubei province and China's epicentre of the novel coronavirus disease (COVID-19) outbreak, April 15, 2020. (Photo by Aly Song/Reuters)

A health official checks the body temperature of a burqa-clad woman passenger amid concerns over the spread of the COVID-19 novel coronavirus at the Lahore Railway station in Lahore on March 19, 2020. (Photo by Arif Ali/AFP Photo)

A woman poses for a photo in front of an installation to promote the film “Godzilla Minus One”, which won the Oscar for best visual effects at the Academy Awards in Los Angeles, outside a popular shopping centre and official development in the Hibiya area of Tokyo on March 11, 2024. (Photo by Richard A. Brooks/AFP Photo)

Polar bears prepare to feast on the remains of a bowhead whale, harvested legally by whalers during their annual subsistence hunt, just outside the Inupiat village of Kaktovik, Alaska, USA, 10 September 2017. As climate change shrinks their natural habitat, polar bears are turning Kaktovik into their very own sanctuary city. (Photo by Jim Lo Scalzo/EPA/EFE)

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)