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)

Tree trunks and rocks are set up to support a leaning wall of Li Yonghua's damaged cave house in an area where land is sinking next to a coal mine, in Helin village of Xiaoyi, China's Shanxi province, August 2, 2016. (Photo by Jason Lee/Reuters)

Nguyen Ngoc Anh, 36, who was an illegal logger turned forest protector poses at Phong Nha National Park, Quang Binh province, Vietnam on April 8, 2022. (Photo by Hoang Trung/Reuters)

A man designs a face mask with the photograph of a customer printed on it, amid the spread of the coronavirus disease (COVID-19), at a photo studio in Gandhinagar, India, May 27, 2020. (Photo by Amit Dave/Reuters)

Composer, harpist and singer Esther Swift alongside her Italian Salvi pedal harp during a photocall ahead of her upcoming tour, at the Forth Bridge in North Queensferry, Scotland on Tuesday, March 7, 2023. Ms Swift will tour across Scotland solo this month with a programme of original compositions and traditional works. (Photo by Jane Barlow/PA Images via Getty Images)

A girl competes in a hobby horsing competition in St. Petersburg, Russia, April 21, 2024. (Photo by Dmitri Lovetsky/AP Photo)

A diver dressed as “Mermaid of the Serpent Depths” performs in front of a sign marking the Lunar New Year of the Snake inside an aquarium at Manila Ocean Park on January 28, 2025. (Photo by Jam Sta Rosa/AFP Photo)

A competitor takes part in the Shrove Tuesday Pancake Race at the City of London's Leadenhall Market on February 13, 2024. (Photo by Isabel Infantes/Reuters)