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)

A Russian-made rifle, carried by this woman when she was captured in Nearby Brush, is slung around her neck by South Vietnamese soldiers before they began their interrogation of her as Viet Cong suspect near AP La Ghi in Vietnam, August 25, 1965. The girl behind the woman, also was captured in the brush. (Photo by AP Photo)

A protester poses for a photo in front of a burning barricade in Barcelona, Spain on February 17, 2021 as a protest following the imprisonment of rapper “Pablo Hasel” convicted to jail for glorifying terrorism and insulting Spain's former king in lyrics turns into riots for a second night. (Photo by Matthias Oesterle/ZUMA Wire/Rex Features/Shutterstock)

A picture taken on April 18, 2020 in Sainte-Croix shows a scultpure representing a man wearing a facemask as a preventive measure against the Covid-19 coronavirus in a field. (Photo by Fabrice Coffrini/AFP Photo)

Peter Carberry riding Gabbys Cross falls off during the Randox Grand National Chase during day three of the Randox Grand National Festival at Aintree Racecourse on April 15, 2023 in Liverpool, England. (Photo by Michael Steele/Getty Images)

Revelers run through the festival grounds to see the next show at the Governors Ball music festival at Corona Park in the Queens borough of New York City, U.S., June 9, 2024. (Photo by Cheney Orr/Reuters)

A robot takes part in what is billed as the world's first robot half marathon during the Humanoid Robot Half-Marathon held in Beijing on Saturday, April 19, 2025. (Photo by Ng Han Guan/AP Photo)

Soldiers ask a tourist to evacuate Mirador beach ahead of Hurricane Beryl's expected arrival in Tulum, Mexico, July 4, 2024. (Photo by Fernando Llano/AP Photo)