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)

“Early morning in Mandawa, rural Rajasthan: it was the morning of Diwali and the streets were swept by smiling women in brightly coloured sarees as I took an early morning cup of chai. Celebrations started later, when darkness fell”. (Photo by Hamish Scott-Brown/Guardian Witness)

Thousands of bright Red Potatoes are washed and sorted at a vegetable market. Workers hose down tons of the vegetables before packing them into sacks at the market in Shibganj Upazila, Bogura, Bangladesh on February 19, 2023. The Red La Soda spuds are then taken to the country's capital Dhaka. (Photo by Mustasinur Rahman Alvi/Rex Features/Shutterstock)

“Cassowaries are large, flightless birds related to emus and (more distantly) to ostriches, rheas, and kiwis”, writes Olivia Judson in the September issue of National Geographic magazine. How large? People-size: Adult males stand well over five foot five and top 110 pounds. Females are even taller, and can weigh more than 160 pounds. Dangerous when roused, they’re shy and peaceable when left alone. But even birds this big and tough are prey to habitat loss. The dense New Guinea and Australia rain forests where they live have dwindled. Today cassowaries might number 1,500 to 2,000. And because they help shape those same forests – by moving seeds from one place to another – “if they vanish”, Judson writes, “the structure of the forest would gradually change” too. (Photo by Christian Ziegler/National Geographic)

A Romanian honor guard soldier stands still as three military aircraft carriers are crossing the sky during a ceremony held at the Unknown Soldier Memorial, in Carol I Park, on the occasion of the Heroes' Day commemoration, in Bucharest, Romania, 10 June 2021. (Photo by Robert Ghement/EPA/EFE)

A man walks pat sculptures with face masks on along an alley in Beijing on August 3, 2021. (Photo by Noel Celis/AFP Photo)

An Egyptian boy rides his donkey in front of a cafeteria with a picture of former Barcelona's forward player Lionel Messi at a village, near Giza, on the outskirts of Cairo, Egypt, February 7, 2022. (Photo by Amr Abdallah Dalsh/Reuters)

A child is seen with persimmons in Denizli, Turkiye on October 24, 2022. (Photo by Ummu Nisan Kandilcioglu/Anadolu Agency via Getty Images)