In Dougie Wallace’s photos of Mumbai taxis, the chatter, yelling, and constant horns of the city are almost audible. A selection of his images is on show at Gayfield Creative Spaces, Edinburgh, as part of the Retina photography festival until 30 July. For four years, the Glasgow-born Wallace focused his photos on one kind of taxi in particular: the Premier Padmini, a 1960s workhorse painted in black and yellow. Locally known as “Kaali-Peeli”, there were once more than 60,000 of them in the Indian city. But thanks to laws restricting pollution, the cars now are fast disappearing from Mumbai’s streets. (Photo by Dougie Wallace/The Guardian)

“Rivers Forgotten” is a journey through the passages and portals of the underground waterways that lie unseen below cities. Self-taught photographer Jeremy Kai brings these forgotten landscapes to light. Photo: Beneath the Toronto area, 2011. (Photo by Jeremy Kai)

Aerial view of CRH bullet trains setting out ahead of Spring Festival travel rush on January 31, 2018 in Hefei, Anhui Province of China. About 2.98 billion trips will be made during the 40-day Spring Festival travel rush. China will take multiple measures to ensure a smooth Spring Festival travel rush. (Photo by VCG/VCG via Getty Images)

A participant works on a laptop on the first day of the 28th Chaos Communication Congress (28C3) – Behind Enemy Lines computer hacker conference on December 27, 2011 in Berlin, Germany. The Chaos Computer Club is Europe's biggest network of computer hackers and its annual congress draws up to 3,000 participants. (Photo by Adam Berry/Getty Images)

Tourist Michel Watson found this pink dolphin making a splash in Brazil. The unusual creature, which hides deep in the Rio Negro river, was spotted leaping out of the Amazonian water brandishing its bizarre bright bubblegum color. Weighing in at nearly 300 pounds, the curious animal, known as an Amazon Pink River Dolphin, looked unusually agile as it rose above the waves. (Photo by Michel Watson)

Children stand in a boat at the banks of the polluted Yamuna River during a dust haze as they wait to give a ride to worshippers in New Delhi during World Environment Day June 5, 2010. (Photo by Reinhard Krause/Reuters)