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)

Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

Victoria Sinitsina and Nikita Katsalapov, of the Russian Olympic Committee, compete in the team ice dance program during the figure skating competition at the 2022 Winter Olympics, Monday, Feb. 7, 2022, in Beijing. (Photo by Jeff Roberson/AP Photo)

Itzhak de Laat of Team Netherlands crashes during the Men's 500m Heats on day seven of the Beijing 2022 Winter Olympic Games at Capital Indoor Stadium on February 11, 2022 in Beijing, China. (Photo by Toby Melville/Reuters)

Naked footballers participate in a Germany v Netherlands soccer match in protest against what they say is increasing commercialization of professional football, in Wuppertal, Germany on September 6, 2020. (Photo by Leon Kuegeler/Reuters)

Apollinariia Panfilova and Dmitry Rylov of Russia perform in the Pairs Short Program during day one of the ISU Grand Prix of Figure Skating Rostelecom Cup at Megasport Arena on November 20, 2020 in Moscow, Russia. (Photo by Evgenia Novozhenina/Reuters)

UK Love Island’s star Maura Higgins, 30, stuns as she poses in revealing outfits in her latest photoshoot with brand Ego in Dubai, United Arab Emirates in April 2021. (Photo by EGO)

Mongolian Chinese performs a traditional Chinese dance in front of the Olympic Rings located near the National Stadium, the main stadium for the 2020 Tokyo Olympic Games in Tokyo, Japan July 29 2021. (Photo by Androniki Christodoulou/Reuters)