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)

Tong Jieping, 44-year-old mentally disabled patient, is chained by his foot inside his room, in Qunxing village of Wangjiang county, Anhui province, China, July 14, 2015. Tong was diagnosed mentally ill when he was in his 20s. His parents, both in their 70s, could not afford the medical treatments so they had to lock him up in chains to prevent him from running away, according to Tong's family. (Photo by Reuters/Stringer)

A white tiger cools off inside its enclosure on a hot summer day at a zoo in Lahore on May 9, 2022. (Photo by Arif Ali/AFP Photo)

A farmer competes in a traditional bull race at Swabi on February 18, 2024. (Photo by Abdul Majeed/AFP Photo)

A youth stands near a cow and a sheep that were sacrified in the village of Miratovc for the celebration of Eid-al-Adha, near the town of Presevo, southern Serbia September 24, 2015. Muslims across the world celebrate the annual festival of Eid al-Adha or the Feast of the Sacrifice. (Photo by Hazir Reka/Reuters)

A picture taken on April 27, 2021, shows the electrical wires running between homes in the capital Baghdad's Murabaa neighbourhood. Between January and March alone, the interior ministry recorded 7,000 fires, the deadliest of which erupted on Sunday in a Covid-19 hospital in Baghdad. Eighty-two people died and 100 others were injured in the inferno, which sparked shock and outrage in the country. Baghdad, a sprawling metropolis of 10 million people, has the tragic distinction of being the Iraqi city hit by the most fires every year. (Photo by Sabah Arar/AFP Photo)

Women take photos on Lake Salt, which is on the UNESCO World Heritage Tentative List, during the sunset in Ankara, Turkiye on July 3, 2023. Lake Salt, which is one of the important wetlands of Turkiye and is of great importance for the protection of biological diversity in our country, also attracts the attention of visitors. (Photo by Aytac Unal/Anadolu Agency via Getty Images)

Bystanders look at the wreckage of a bus in Noshki town of Balochistan province on March 17, 2025, a day after an explosives laden car hit one of the seven buses of a convoy, a bombing carried out allegedly by the separatist group Baloch Liberation Army (BLA). Separatists in southwest Pakistan killed at least five paramilitaries and wounded more than 30 on March 16, police told AFP, days after an attack on a train in Balochistan province left dozens dead. (Photo by AFP Photo)