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 woman picks marigold flowers used to make garlands and offer prayers, before selling them to the market for the Tihar festival, also called Diwali, in Kathmandu, Nepal on October 17, 2017. (Photo by Navesh Chitrakar/Reuters)

A snail slithers up a rain spattered window during stormy weather on the Isle of Portland, Fortuneswell, England on July 29, 2018. (Photo by Stuart Fretwell/Rex Features/Shutterstock)

A group of PETA supporters protest Canada Goose's use of coyote fur, with “Canada Goose Kills” painted on their backs in New York, USA on October 18, 2018. (Photo by Erik Pendzich/Rex Features/Shutterstock)

A view through mist shows the Kirk of Saint Mary Magdalene in Primorsk, Leningrad Region, Russia on March 24, 2019. (Photo by Anton Vaganov/Reuters)

A service member of the Ukrainian armed forces is seen at fighting positions on the line of separation from pro-Russian rebels in Donetsk region, Ukraine on April 10, 2021. (Photo by Oleksandr Klymenko/Reuters)

Turkish police detained dozens of demonstrators participating in an LGBT pride march in Istanbul, Turkey on June 26, 2021. Police fired tear gas, rubber bullets and blocked attempts by protesters to gather in large numbers after a government decision to ban pride events in recent years. (Photo by Diego Cupolo/NurPhoto/Rex Features/Shutterstock)

A bomb-laden Su-25 jet at the Hmeimim air base in December 2015. Russia's lease agreement obliged Assad’s military to safeguard the perimeter of the Hmeimim base, while giving Moscow legal jurisdiction over the facilities inside. Negotiating perimeter protection from Syria’s new rulers will be vital for the Russian bases in an era of wire-controlled drones immune to jamming. (Photo by AP Photo)