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 Saudi trader wears a mask as he monitors stock information at the Saudi stock market in Riyadh, Saudi Arabia on August 25, 2020. (Photo by Ahmed Yosri/Reuters)

Garrett Gerloff (L) of the USA GRT Yamaha WorldSBK Junior Team and Sandro Cortese (R) of Germany on OUTDO Kawasaki TPR colide during a warm up session of the the World Superbike Championship on Phillip Island, Victoria, Australia, 01 March 2020. (Photo by Scott Barbour/EPA/EFE)

An Chelsea supporter takes pictures next to the giant inflatable replica of the UEFA Champions League trophy placed at Aliados Avenue in Porto, Portugal, 27th May 2021. Porto hosts the UEFA Champions League final between Manchester City and Chelsea in 29th May 2021. (Photo by Jose Coelho/EPA/EFE)

American actress, model, and singer Ashley Benson arrives at Paris Hilton's wedding party inBeverly Hills, CA. on November 14, 2021. (Photo by Backgrid USA)

Racegoers in fashionable hats attend Ladies Day at Cheltenham Festival on March 15, 2017 in Cheltenham, England. (Photo by David Davies/PA Wire)

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)

Pakistan girls make selfies holding a Pakistan-made weapon displayed at the four-day International Defence Exhibition and Seminar (IDEAS) 2016 in Karachi, Pakistan, Wednesday, November 23, 2016. (Photo by Shakil Adil/AP Photo)