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)

These heart-warming photograph show an incredible bond between a wild lioness and the men fighting to save her species. The picture show Sirga – a 110lb lioness – and her adopted pride Valentin Gruener (not pictured) and Mikkel Legarth. Incredibly she treats the two men just like she would other lions and with their help she can now hunt for prey on her own. As a cub she was driven out from a pride and rescued by German and Danish duo Valentin and Mikkel who could not stand by and watch her die. She is now a beacon for hoped success of the Modisa Wildlife Project, founded in Botswana, Africa, by Valentin and Mikkel with the hope of saving the lion population. (Photo by Caters News)

Tanzania, 1964. A touching moment between primatologist and National Geographic grantee Jane Goodall and young chimpanzee Flint at Tanzania's Gombe Stream Reserve. (Photo by Hugo van Lawick via National Geographic)

A leopard leaps into a muddy waterhole to catch a fish on August 13, 2015, in the Savuti Channel in Botswana. A leopard leaps into a muddy waterhole to catch a fish in the Savuti Channel in Botswana. The spotted predator stood poised waiting for a fish to appear – before leaping in ferociously with lightening reflexes. Coated in a layer of thick dark mud the big cat emerged from the water clutching the fish in its jaws. The fishing leopards of Savuti are known for their unique skills in catching fish – but have rarely been photographed. (Photo by Greatstock/Barcroft Media)

This photograph, taken on September 28, 2019, shows an Erythrina Abyssinica planted in a pasture on Ferme Espoir, owned by former President Joseph Kabila, in Masisi territory, northeast of the Democratic Republic of Congo. (Photo by Alexis Huguet/AFP Photo)

Elephants forage for food at a rubbish dump encroaching on their jungle habitat in Oluvil, Sri Lanka in September 2020. Examination of dead elephants has revealed undigested polythene and other plastic waste. (Photo by Tharmaplan Tilaxan/Cover Images)

A woman clatters pans to make noise after calls for protest went out on social media in Yangon on February 3, 2021, as Myanmar's ousted leader Aung San Suu Kyi was formally charged on Wednesday two days after she was detained in a military coup. (Photo by AFP Photo/Stringer)

Mount Etna erupts near Sicily, Italy on March 15, 2021. This is the thirteenth time in twenty-eight days. During the early evening of 14 March and the night between 14 and 15 March a strombolian activity at the Southeast Crater gradually increased, leading to a paroxysmal event which had its peak around 01:00 am, ash blown by the wind touched the south-southeast slope of the volcano reaching also Catania, the event ceased completely around 3:45, photo taken from Milo near Catania on March 15, 2021. (Photo by Salvatore Allegra/Anadolu Agency via Getty Images)