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)

Ahmed, a 10-year-old jockey, looks on during the opening of the International Camel Racing festival at the Sarabium desert in Ismailia, Egypt, March 21, 2017. (Photo by Amr Abdallah Dalsh/Reuters)

This aerial photo taken on December 28, 2018 shows commercial and residential buildings in Hong Kong. (Photo by Dale De La Rey/AFP Photo)

Migratory flamingos arriving from Europe are seen in Port Fouad Nature Reserve, on the outskirts of Port Said Governorate, Egypt on December 12, 2022. (Photo by Mohamed Abd El Ghany/Reuters)

Ukrainian soldiers fire the D-30 artillery to Russian positions in the direction of Klishchiivka as the Russia-Ukraine war continues in Donetsk Oblast, Ukraine on August 12, 2023. (Photo by Diego Herrera Carcedo/Anadolu Agency via Getty Images)

Commuters, some of them wearing masks as a precaution against the coronavirus ride an auto-rickshaw in Noida, outskirts of New Delhi, India, Thursday, July 16, 2020. (Photo by Altaf Qadri/AP Photo)

Sophia answers questions at Hanson Robotics studio in Hong Kong on March 29, 2021. Sophia is a robot of many talents — she speaks, jokes, sings and even makes art. In March, she caused a stir in the art world when a digital work she created as part of a collaboration was sold at an auction for $688,888 in the form of a non-fungible token (NFT). (Photo by Vincent Yu/AP Photo)

Rapper Cardi B is seen in Paris, France on September 30, 2019 at Paris Fashion Week. (Photo by Splash News and Pictures)