Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

Sunset on Monday evening, June 17, 2024 at Mudeford in Dorset, UK with a swan stretching it's wings. (Photo by Cenk Albayrak-Touye/Picture Exclusive)

Young girls dress up in traditional costumes and pose for a selfie at the opening ceremony of the Leishan Miao new year festival in the city of Kaili, Guizhou province, China on November 23, 2015. (Photo by Imaginechina/Rex Shutterstock)

Parade-goers walk in the annual West Indian Day Parade on September 02, 2019 in the Brooklyn borough of New York City. The annual celebration of Caribbean culture is one of the largest of its kind and features dozens of floats and costumed participants that make their way down Flatbush Avenue. (Photo by Yana Paskova/Getty Images)

Surfer Gary Clisby rides his foil board on a morning swell of the coast of Carlsbad, California on May 23, 2018. Harnessing the “foiling” technology more typically seen on racing catamarans in sailing's America's Cup, the surfboards appear to fly above the water thanks to a fin attached to the bottom of the board. (Photo by Mike Blake/Reuters)

American actress, model, singer and activist Paris Jackson attends Comic-Con in San Diego, California, USA on July 21, 2018. (Photo by @parisjackson/Instagram)

Li Guoqiang talks on his phone outside his house at Guangfuli neighbourhood, in Shanghai, China, April 1, 2016. Li, 38, is a deliveryman who rents a place at Guangfuli. In a corner of Shanghai, surrounded by a cement wall, lies one of the world's most valuable fields of debris and garbage. On paper, the Guangfuli neighbourhood is a real estate investor's dream: a plot in the middle of one of the world's most expensive and fast-rising property markets. But the reality is more like a developer's nightmare, thanks to hundreds of people living there who have refused to budge from their ramshackle homes for nearly 16 years as the local authority sought to clear the land for new construction. (Photo by Aly Song/Reuters)

Polar Bear club swimmers take their annual swim in the sea at Coney Island in New York City on January 1, 2014. (Photo by Curtis Means/ACE/INFphoto.com)