It’s enough to make your head spin. The photographer Katherine Young set out to shoot spiral staircases in London, England to great effect, including this shot she calls the Downward Spiral Part III. (Photo by Katherine Young/Rex Features/Shutterstock)

In this February 22, 2018 photo, a couple looks at a bag made out of Venezuelan Bolivars in La Parada, Colombia, on the border with Venezuela. Each collector item produced by Richard Segovia, sitting at the table, fetches between $10 and $15 – a huge markup from the pennies that bolivars retrieve on Venezuela's black market. (Photo by Fernando Vergara/AP Photo)

Baka pygmies in their forest home preparing food in, Sangha Forest, Central African Republic, February 2016. Here, in their forest home, traditional life continues in the face of multiplying challenges ranging from poachers, to ill health. Deep in the rainforests of central Africa lives one of the world’s most mysterious tribes. (Photo by Susan Schulman/Barcroft Images)

From footballs to live fish, delivery mopeds piled high with unwieldy, unlikely goods are one of the Vietnamese capital’s most distinctive sights. As the city plans to ban motorbikes altogether, photographer Jon Enoch captured the drivers at work. (Photo by Jon Enoch/The Guardian)

Winner. “I took this vertical image in the Quarry Bay district of Hong Kong during the dusk ‘blue hour’, when there was a perfect balance between the ambient light in the sky and the artificial lights of the high-rise residential buildings”. (Photo by Jatinder Heer/The Guardian)

Runner-up. “The City of London, looking towards the Royal Exchange and the Bank of England. The ever-changing London skyline provides many excellent opportunities for cityscape photography, none more exciting than the ebb and flow of traffic at night”. (Photo by Mark Caldon/The Guardian)

The sun rises between Sgurr nan Gillean and Knight’s Peak, Black Cuillin, Isle of Skye. (Photo by Adrian Trendall/Mountain Photo of the Year)

Bill Moreau watches as the Black Forest fire burns near his house near Black Forest Road Tuesday afternoon, June 11, 2013, near Colorado Springs, Colo. The Black Forest Fire was one of at least three significant wildfires burning in Colorado amid gusty winds and record-breaking hot, dry weather. (Photo by Christian Murdock/AP Photo/The Colorado Springs Gazette)