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)

This Thursday, April 30, 2015 photo shows Lebanese citizens walking on the Corniche, or waterfront promenade in Beirut, Lebanon. This photo was shot through the lowered veil of a niqab, which is worn by some conservative Muslim women. The cloth allows women to follow a strict interpretation of their religious beliefs by preventing others from seeing their faces. (Photo by Hassan Ammar/AP Photo)

A picture made available on 17 July 2015 shows the bright line of the Milky Way above the old oaks at the Rogalin landscape Park in Rogalin village, near Poznan, on the night of 16 July 2015. (Photo by Lukasz Ogrodowczyk/EPA)

A worker spreads paddy crop for drying in a rice mill complex on the outskirts of Ahmedabad February 3, 2011. (Photo by Amit Dave/Reuters)

Maria Sakkara of Greece in action against Ann Li of the United States in her second round match at the Qatar TotalEnergies Open at the Khalifa International Tennis & Squash Complex on February 22, 2022 in Doha, Qatar (Photo by Robert Prange/Getty Images)

A male elephant named Mahadevan is tied in a truck as he is being transported for an annual temple festival in Kochi, India, March 10, 2020. (Photo by Sivaram V/Reuters)

A drag queen goes through security a RuPaul’s DragCon in Los Angeles, USA on May 26, 2019. (Photo by Ronen Tivony/SOPA Images/Rex Features/Shutterstock)

A life-size replica of a Diplodocus dinosaur watches people coming out of the subway in the city center of Bochum, Germany, Monday, August 12, 2019. The exhibition, featuring models of 33 dinosaurs all around the city center, is in Bochum due to the discovery of an 316 million years old dinosaur track found in a stone pit in the city six years ago. (Photo by Martin Meissner/AP Photo)