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)

Christie Brinkley is seen walking in midtown on August 21, 2019 in New York City. (Photo by Raymond Hall/GC Images)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Aerial view of tourists in life vests and rubber rafts in the Grand Canyon of western Henan, Sanmenxia, China on August 5, 2017. (Photo by Imaginechina/Rex Features/Shutterstock)

A lion rests in the Nairobi National Park, Kenya on January 6, 2021. (Photo by Tiksa Negeri/Reuters)

Montegut fire chief Toby Henry walks back to his fire truck in the rain as firefighters cut through trees on the road in Bourg, Louisiana as Hurricane Ida passes on August 29, 2021. Hurricane Ida struck the coast of Louisiana on August 29 as a powerful Category 4 storm, 16 years to the day after deadly Hurricane Katrina devastated the southern US city of New Orleans. “Extremely dangerous Category 4 Hurricane Ida makes landfall near Port Fourchon, Louisiana”, the National Hurricane Center wrote in an advisory. (Photo by Mark Felix/AFP Photo)

A woman, wearing a traditional Sevillana dress, performs as she asks for alms in downtown Malaga, Spain, April 28, 2016. (Photo by Jon Nazca/Reuters)

A villager stretches as the Mayon volcano spews ashes and lava in Legaspi city, Albay province, Philippines, 12 June 2023. The restive Mayon volcano has begun spewing lava and small eruptions, putting the lives of thousands of people at risk from possible violent explosion. (Photo by Francis R. Malasig/EPA/EFE)