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)

Naked footballers participate in a Germany v Netherlands soccer match in protest against what they say is increasing commercialization of professional football, in Wuppertal, Germany on September 6, 2020. (Photo by Leon Kuegeler/Reuters)

Three pals pose for a picture on a night out in Liverpool city centre, United Kingdom on December 24, 2020. Festive boozers braved the cold in Liverpool and York – as millions down South rang in Christmas Day indoors due to Covid restrictions. (Photo by David Nelson/South West News Service)

Reality TV personality Kim Kardashian speaks alongside US President Donald Trump during a second chance hiring and criminal justice reform event in the East Room of the White House in Washington, DC, June 13, 2019. (Photo by Saul Loeb/AFP Photo)

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)

A protester reacts during a rally against the government's restrictions following the coronavirus disease (COVID-19) outbreak, in Berlin, Germany, August 29, 2020. (Photo by Christian Mang/Reuters)

A woman reacts as she receives the AstraZeneca/Oxford vaccine under the COVAX scheme against coronavirus disease (COVID-19) at the Kenyatta National Hospital in Nairobi, Kenya on March 5, 2021. (Photo by Monicah Mwangi/Reuters)

Katie Loynes of the Blues attempts to mark the ball during the AFLW Preliminary Final match between the Carlton Blues and the Fremantle Dockers at Ikon Park on March 23, 2019 in Melbourne, Australia. (Photo by Mike Owen/Getty Images)