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)

Swimmers in the Sky Pool, a transparent swimming pool suspended 35 meters above ground between two apartment buildings, during hot weather in Nine Elms, central London on Monday, August 12, 2024. (Photo by James Manning/PA Images via Getty Images)

A remote-controlled plane in the form of a witch flies over a neighborhood as the sun sets during Halloween in Encinitas, California, U.S. October 31, 2016. (Photo by Mike Blake/Reuters)

A worker roasts a row of pigs on bamboo poles at a roasting pit, in Manila, Philippines, December 21, 2020. (Photo by Lisa Marie David/Reuters)

“Drag Race Thailand” contestants Thanisorn Hengsoontorn “Annee Maywong” (L) and Supattarapon Kasikam “Dearis Doll” pose at a studio in Bangkok, Thailand March 23, 2018. (Photo by Athit Perawongmetha/Reuters)

A tourist takes photos among fireweed, or kochia scoparia, at an archaeological site park on September 13, 2022 in Xi'an, Shaanxi Province of China. (Photo by Zhang Yuan/China News Service via Getty Images)

A Ukrainian service member shoots from a machine gun at a position on the front line, amid Russia's attack on Ukraine, near the town of New York, Donetsk region, Ukraine on June 9, 2022. (Photo by Gleb Garanich/Reuters)

A girl competes in a hobby horsing competition in St. Petersburg, Russia, April 21, 2024. (Photo by Dmitri Lovetsky/AP Photo)