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)

Thai officials arrive for morning alms as part of celebrations for the 68th birthday of Thai King Maha Vajiralongkorn Bodindrade​bayavarangkun, at Sanam Luang in Bangkok, Thailand, 28 July 2020. (Photo by Diego Azubel/EPA/EFE)

English singer, songwriter and model Sophie Ellis-Bextor performs at G-A-Y at The Astoria on February 17, 2007 in London, England. (Photo by Jo Hale/Getty Images)

Woman and man playing domination games in bed. (Photo by NDAB Creativity/Rex Features/Shutterstock)

Jellyfish with a juvenile imperial blackfish (Schedophilus ovalis) in Castellammare di Stabia, Naples, Italy, winter 2023. (Photo by Marco Gargiulo/Media Drum Images)

The sunrise over the beach huts at Hamworthy Park in Poole, Dorset, United Kingdom on April 28, 2022. (Photo by Rachel Baker/Bournemouth News)

A woman uses a tree branch to fight a fire on the road leading to the village of Parada, near Mortagua, northern Portugal, Thursday, August 11 2016. Firefighters in Portugal are battling multiple blazes fed by brush in a hot, dry summer for a sixth straight day. Major fires have also been raging in northwestern Spain and southern France. (Photo by Sergio Azenha/AP Photo)

Australian Aboriginal hunter Marcus Gaykamangu of the Yolngu people, carries an Australian native lizard called a goanna over his shoulder as he walks away from a billabong near the “out station” of Yathalamarra, located on the outksirts of the community of Ramingining in East Arnhem Land November 22, 2014. (Photo by David Gray/Reuters)