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)

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

People work with cocoa beans in Enchi June 17, 2014. Picture taken June 17, 2014. Ghana emerged as a success story during the 2000s, when war, political instability and a disastrous liberalization brought Ivory Coast's cocoa sector to its knees. Ghana's output more than tripled from 340,000 tons in the 2001/02 season to a record 1,025,000 tons a decade later. Strict controls cemented its reputation as a producer of top quality beans, establishing a brand that fetches a premium. (Photo by Thierry Gouegnon/Reuters)

An operator adjusts a film projector during a wedding party in Bogor, Indonesia, February 18, 2017. Indonesian entrepreneur Kamaluddin loves the gritty look of old 35-millimeter film so much that he spends most of his nights screening vintage movies at weddings and parties around Jakarta, the capital. (Photo by Reuters/Beawiharta)

“Mr Big Dipper”, Nicholas Roemmelt (Denmark). A stargazer observes the constellation of the Big Dipper perfectly aligned with the window of the entrance to a large glacier cave in Engadin, Switzerland. This is a panorama of two pictures, and each is a stack of another two pictures: one for the stars and another one for the foreground, but with no composing or time blending. (Photo by Nicholas Roemmelt/National Maritime Museum/The Guardian)

Cha Huilan, a 40-year old Lisu woman, and her daughter leave Lazimi village with a zipline across the Nu River in Nujiang Lisu Autonomous Prefecture in Yunnan province, China, March 24, 2018. Chinese mountain villagers, cut off from shops and churches by a raging river, use a zipline to cross its violent rapids and jagged rocks. (Photo by Aly Song/Reuters)

Kritchaya “Lolita” Boonhor (R) curls her eyelashes in ladyboy Candy's (L) room while she chats her about her boyfriend, in Bangkok, Thailand, 27 November 2017. Most things in life are a question of negotiation. Lolita is a woman, that was not to be negotiated. What needed to be negotiated was how she was perceived by those around her. And that negotiation was one that took time and effort. (Photo by Lola Levan/EPA/EFE)

A navy diver storms into the gallery during a military display at Singapore's 52nd National Day celebrations at Marina Bay in Singapore August 9, 2017. (Photo by Edgar Su/Reuters)