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)

“The Reward”. “A spot that a friend and I found that takes a bit of effort to get to. Needs the right swell and wind direction to come together for the backwash to really happen. We had been many times with OK results, but this morning everything lined up perfectly and I was rewarded with this split-second moment in time under some amazing morning light”. (Photo by Scott Harrison/2019 UK Surf Photo of the Year)

People enjoying the hot weather on Brighton beach in Sussex, England on August 7, 2020. (Photo by Stephen Lock/i-Images)

Flames from the LNU Lightning Complex fires consume a home in unincorporated Napa County, Calif., on Wednesday, August 19, 2020. Fire crews across the region scrambled to contain dozens of wildfires sparked by lightning strikes. (Photo by Noah Berger/AP Photo)

Swimmers in fancy dress take part in a Christmas Day dip at Exmouth, Devon, England, Saturday, December 25, 2021. (Photo by Ben Birchall/PA Wire via AP Photo)

A drone view shows people surfing during spring sunshine, as the warm weather is set to continue into the weekend, at Fistral Beach, Newquay, south west Britain, on May 9, 2024. (Photo by Toby Melville/Reuters)

An Iranian woman wearing a face mask walks on a street in Tehran, Iran, 19 October 2020. According to the Iranian Health ministry, Iran reported its highest daily COVID-19 death toll of 337 and 4,251 new infections in past 24 hours as it appears that Iran is in a third wave of COVID-19 outbreak. (Photo by Abedin Taherkenareh/EPA/EFE)

Lucie Clayton instructs pupils in the art of correct posture by balancing a glass and book on their heads at her finishing school in Old Cavendish Street, London. (Photo by William Vanderson/Fox Photos/Getty Images). 25th November 1936