View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)

Melanie Chisholm, Emma Bunton, Melanie Brown and Geri Horner of the Spice Girls in concert at Wembley Stadium in London on Sunday, June 16, 2019. (Photo by Andrew Timms/PA Wire)

Brown bear cubs eat out of garbage bins at a residential area near the forest in Sarikamis district of Kars, Turkiye on May 30, 2023. (Photo by Huseyin Demirci/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)

Participants kiss on a platform as they take part in the annual event “No Trousers Tube Ride” in London, Sunday, January 8, 2023. The No Trousers Tube Ride returns to London, the first time the event had taken place since January 2020, due to Covid. (Photo by Kin Cheung/AP Photo)

Indian boy Hassan Malik works in a leather shoe factory at Topsia in Calcutta, eastern India, 19 November 2013. The leather industry occupies an important place in the Indian economy. It is an employment intensive sector with a vast potential for growth and exports but also a pollution intensive industry that relies on cheap labor. One of the major production centers for leather and leather products is located in Calcutta, West Bengal. Hundreds of tanneries are operated in the city’s Tiljala, Topsia and Tangra districts. They are mostly run by local families living and working under poor conditions. (Photo by Piyal Adhikary/EPA)

Performers dressed as Ded Moroz, the equivalent of Santa Claus, and his granddaughter Snegurochka (Snow Maiden) take on shoe covers as they visit the Republican Scientific and Practical Centre of Pediatric Surgery in Minsk, Belarus, December 28, 2016. (Photo by Vasily Fedosenko/Reuters)