A man wearing a costume dives into a partly frozen lake in Shenyang, in China's northeastern Liaoning province on February 19, 2019. (Photo by AFP Photo/China Stringer Network)
A girl dives under a wave at Bondi Beach as temperatures reached 29 degrees celsius on December 17, 2020 in Sydney, Australia. The Bureau of Meteorology predicted the arrival of thunderstorms and showers later today with a southerly change bringing possible severe storms around the Sydney region. (Photo by Mark Evans/Getty Images)
A member of a local swimming club holds a Russian national flag as he dives in at the start of a 24-hour swimming marathon near the western Siberian city of Barnaul March 29, 2014. Thirty members of the club will swim in turn during the event, held to mark Crimea becoming part of Russia, local media reported. (Photo by Andrei Kasprishin/Reuters)
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 large bull walrus returns to the shores of Prins Karl Forland after diving and feeding on clams. (Photo by Paul Nicklen/National Geographic). Svalbard, Norway, 2011