People kiss before the start of the Carmelitas street party on the first day of Carnival in Rio de Janeiro, Brazil, Friday, February 9, 2024. (Photo by Bruna Prado/AP Photo)

Team Spain perform their routine during the Team Technical during the World Aquatics Artistic Swimming World Cup 2024 - Stop 2 at Aquatics Centre on May 03, 2024 in Paris, France. (Photo by Adam Pretty/Getty Images)

Kylian Mbappe of France celebrates his second goal during the FIFA World Cup Qatar 2022 Round of 16 match between France and Poland at Al Thumama Stadium on December 4, 2022 in Doha, Qatar. (Photo by Fabrizio Bensch/Reuters)

Croatia's Josko Gvardiol reacts after Argentina's Julian Alvarez scored his side's second goal during the World Cup semifinal soccer match between Argentina and Croatia at the Lusail Stadium in Lusail, Qatar, Tuesday, December 13, 2022. (Photo by Martin Meissner/AP Photo)

A captive elephant is made to swim for visitors at Khao Kheow Open Zoo in Chonburi province, Thailand on September 15, 2024. (Photo by Lillian Suwanrumpha/AFP Photo)

Ukrainian soldiers fire with D-30 artillery at Russian positions in the direction of Klishchiivka as the Russia-Ukraine war continues in Donetsk Oblast, Ukraine on August 12, 2023. (Photo by Diego Herrera Carcedo/Anadolu Agency via Getty Images)

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)

People cheer as the ball drops at midnight in Times Square on January 1, 2015 in New York City. An estimated one million people from around the world are expected to pack Times Square to ring in 2015. (Photo by Andrew Theodorakis/Getty Images)