A worker cleans the statue of Yuri Gagarin, the first person who flew to space, ahead of Cosmonautics Day celebrated on April 12, in Moscow, Russia, Wednesday April 10, 2019. Cosmonautics Day marks when Soviet cosmonaut Yuri Gagarin became the first man to fly in space, in 1961, orbiting the earth once before making a safe landing. (Photo by Maxim Marmur/AP Photo)

Health workers wearing face masks spray disinfectant liquid on sacrificial animals amid concerns over the spread of the SARS-CoV-2 coronavirus that causes the pandemic COVID-19 disease ahead of the Muslim festival of Eid al-Adha at an animal market in Hyderabad, southern Pakistan, 21 July 2020. (Photo by Nadeem Khawar/EPA/EFE)

Princess Diana relaxes on the sand during a visit to the beach on the Caribbean Island of Nevis January 4, 1993. (Photo by Mark Cardwell/Reuters)

Adolf Hitler (left), German Nazi politician, in a deck chair next to is niece Angela (Geli) Raubal – around 1930. (Photo by Ullstein Bild/Ullstein Bild via Getty Images)

Students dressed as Hindu Lord Shiva, also known as Nataraja, the Lord of Dancers, during a religious event in Mumbai, India, August 30, 2018. (Photo by Francis Mascarenhas/Reuters)

An old woman looks from inside a car with bullet holes and shattered windows as she flees fighting in the eastern Ukrainian town of Slaviansk June 9, 2014. REUTERS/Gleb Garanich.

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)