Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

Two holidaymakers amuse themselves with a porter's trolley whilst waiting for their train at Euston Station, London, 5th August 1939. (Photo by A. J. O'Brien/Fox Photos/Getty Images)

Pakistan girls make selfies holding a Pakistan-made weapon displayed at the four-day International Defence Exhibition and Seminar (IDEAS) 2016 in Karachi, Pakistan, Wednesday, November 23, 2016. (Photo by Shakil Adil/AP Photo)

At a “Guts” tour stop in Seattle, American singer-songwriter Olivia Rodrigo in the first decade of August 2024 basks in the glow her ensemble creates. (Photo by Olivia Rodrigo/Instagram)

A trio poses for a photo in front of the art installation Surrender (Flag) by John Gerrard of Ireland displayed in a courtyard of the Palacio de San Francisco, as part of the first art biennial in Bogota, Colombia, Tuesday, September 23, 2025. (Photo by Fernando Vergara/AP Photo)

Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

Policewomen take a picture inside a tunnel under the Chao Phraya river at a Mass Rapid Transit subway station in Bangkok, Thailand, December 14, 2015. (Photo by Athit Perawongmetha/Reuters)

Bella Thorne out and about, Los Angeles, USA on June 14, 2017. (Photo by Broadimage/Rex Features/Shutterstock)