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)

A girl jumps to touch cherry blossoms in full bloom in Fussa, outskirts Tokyo, Japan, 05 April 2014. Temperatures being very constant made blossoms to keep full bloom for holiday makers. (Photo by Kimimasa Mayama/EPA)

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)

Commonwealth dance group on the right track with Virgin Trains – Photo call at Glasgow Central Station. (Photo by Daily Record)

Women sing and dance as children gather in the background during the so-called parade of children's troops in Rostov-on-Don, southern Russia, May 14, 2015. About 500 children aged from 4 to 10, members of youth military patriotic clubs, honor guards and paratroopers took part in the event, which was organized under the guidance of Commander of Southern Military District Colonel-General Alexander Galkin and was held to honor World War Two veterans and mark the 70th anniversary of the victory over Nazi Germany, according to local media. (Photo by Eduard Korniyenko/Reuters)

Journalists watch the take off of a German Eurofighter jet at the airbase in Noervenich, Germany, Thursday, August 20, 2020. Pilots from Israel and Germany will fly together the next two weeks during the first joint military Air Force exercises between the two nations in Germany. (Photo by Martin Meissner/AP Photo)

Girls wearing protective face masks wait to pray inside temple premises on the occasion of the annual harvest festival of Onam on the outskirts of Kochi, India, August 31, 2020. (Photo by Sivaram V/Reuters)

A woman dressing the traditional clothes of a “cholita”, skates during a skate festival on September 30, 2020 in La Paz, Bolivia. According to the Johns Hopkins University Resource Center, Bolivia has over 130,000 confirmed cases of Covid-19 and more than 7,500 deceases. (Photo by Gaston Brito/Getty Images)