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)

Storm clouds blanket the sky over Great American Ball Park as Starlin Castro #13 of the Chicago Cubs fields a ground ball in the fifth inning against the Cincinnati Reds as on July 7, 2014 in Cincinnati, Ohio. (Photo by Jamie Sabau/Getty Images)

A layer of morning mist still covers the fields as the sun rises into the morning sky over Hohenfelden, Thuringia state, Germany, early 07 September 2016. Meteorologists predict the weather to become warm and sunny in the region with temperatures reaching around 256 degrees Celsius. (Photo by Martin Schutt/EPA)

A Nepalese woman pours milk as she offers prayers to the setting Sun on the banks of the Bagmati River during the Chhath Puja festival in Kathmandu, Nepal, Sunday, November 6, 2016. During Chhath, an ancient Hindu festival, rituals are performed to thank the Sun God for sustaining life on earth. (Photo by Niranjan Shrestha/AP Photo)

A person viewing the Northern lights over the lava landscape, Reykjanes Peninsula, Iceland. (Photo by Arctic-Images/Getty Images)

A veterinarian from the zoo of Besancon feeds “Soa”, a female crowned sifaka, in Besancon, eastern France, on February 18, 2019. The crowned sifaka is a critically endangered species from Madagascar. There were only 6 females over 20 individuals living in 7 zoos worldwide end of 2018. (Photo by Sébastien Bozon/AFP Photo)

A family tries to cross a flooded road amid gushing water in Kolkata, India on August 17, 2019. Heavy rain continues for a second day in Kolkata, which contuinued to flood many streets all around the city. Authorities are working overtime to clear the roads. (Photo by Debarchan Chatterjee/Zuma Wire/Rex Features/Shutterstock)

Two young dancers take pictures while waiting for the start of the Koenji Awa-Odori dance festival, in the Koenji neighborhood of Tokyo. Saturday, August 24, 2019, Started in the 1950s, the Koenji Awa-Odori has grown to be one of Tokyo's largest and most popular summer festivals an estimated 10,000 dancers participating in the dance festival. Hundreds of thousands of spectators gather in the neighborhood to watch the two-day summer spectacle. The event is held on the last weekend of August each year. (Photo by Jae C. Hong/AP Photo)