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)

Aidan Thomas wears a Smokey Bear t-shirt as he watches smoke from the Airport Fire rise behind Meander Lane in Trabuco Canyon, Calif., on Monday, September 9, 2024. (Photo by Jeff Gritchen/The Orange County Register via AP Photo)

Families and children play at Brimham Rocks during their half term break in North Yorkshire, UK on February 18, 2025. (Photo by James Glossop/The Times & Sunday Times)

A person viewing the Northern lights over the lava landscape, Reykjanes Peninsula, Iceland. (Photo by Arctic-Images/Getty Images)

A man watches the huge waves which brakes at the Paseo Nuevo's promenade in San Sebastian, Basque Country, Spain on 11 January 2016 where the wind has reached to 90 km/h and have been registred waves of eight kilometres due to the bad weather. (Photo by Juan Herrero/EPA/EFE)

A man watches a wave hit a rock pool at Curl Curl beach as large swell hits the East Coast of Australia on June 6, 2016 in Sydney, Australia. Torrential rain over the weekend saw streets and homes flooded while wind gusts up to 120km per hour brought down trees and powerlines. A king tide has also seen beachside homes evacuated on Sydney's northern beaches as large waves erode the coast. (Photo by Cameron Spencer/Getty Images)

A person sits in a chair next to the Garzweiler lignite opencast mine at the Luetzerath village near Erkelenz, Germany, Tuesday, January 10, 2023. Environmental activists were locked in a standoff with police this week around the hamlet of Luetzerath that's due to be bulldozed for the expansion of a nearby lignite mine. (Photo by Michael Probst/AP Photo)

People walk along Beachy Head, close to Eastbourne on the south coast of England on April 12, 2020, as life in Britain continues over the Easter break, during the nationwide lockdown to combat the novel coronavirus pandemic. Britain's Prime Minister Boris Johnson was making “very good progress” on Saturday in his recovery in hospital from coronavirus, officials said, as the country's deaths toll from the disease approached the grim milestone of 10,000. (Photo by Ben Stansall/AFP Photo)