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)

Michael O’Neill won a prize in animal portraits with fry of a peacock bass hovering around their mother for protection against predators in South Florida. (Photo by Michael Patrick O'Neill/2016 National Geographic Nature Photographer of the Year)

Inspired by traditional Indian travelling photography studios, Arthur Crestani photographed the inhabitants of Gurgaon, a city built almost entirely by private companies. Arthur Crestani’s “Bad City Dreams” contrasts the glossy ideal sold by developers with urban reality. Here: Luxury Living Bhiwadi: “Sky Club on 18th Floor”. (Photo by Arthur Crestani/The Guardian)

Model Alessandra Ambrosio is seen at Coachella Music & Arts Festival at the Empire Polo Club on Friday, April 14, 2017, in Indio, Calif. (Photo by Hollywood To You/Star Max/GC Images)

Amanda Lepore attends the “Doll Parts” book launch party at The Standard, Highline on April 18, 2017 in New York City. (Photo by J. Kempin/Getty Images)

A giant panda cub falls from the stage while 23 giant pandas born in 2016 seen on a display at the Chengdu Research Base of Giant Panda Breeding in Chengdu, Sichuan province, China, September 29, 2016. (Photo by Rex Features)

A mermaids swims during MerMagic Con at the Freedom Aquatic Center in Manassas, Virginia on August 7, 2021. MerMagic Con is advertised as the largest Mermaid convention in the world. Some parts of the convention are based on modeling and looks like the Miss Mermaid USA Pageant. The Society of Fat Mermaids looks to bring together plus size people and promote the idea that anyone can become a mermaid. Becoming a mermaid is not cheap, most merfolk spend thousands of dollars on their tail and outfit. Most tails are custom made out of silicone and others are foam and fabric. (Photo by Joseph Prezioso/AFP Photo)

A group of people walk on the sea wall as a man kayaks through the flooded parking lot in downtown Annapolis, Maryland, on October 29, 2021. The US National Weather Service implemented a flood watch for the cities of Baltimore and Annapolis as well as Anne Arundel, Baltimore and Howard counties. Washington, DC, and parts of Virginia faced the same alert. (Photo by Jim Watson/AFP Photo)