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)

A trader speaks on the phone at his desk at the Frankfurt stock exchange, Germany, in this June 29, 2015 file photo. Federal Reserve policymakers are widely seen raising interest rates for the first time in almost a decade at their next meeting this week. (Photo by Ralph Orlowski/Reuters)

A mechanical horse-dragon made of wood and steel is presented to the public in Nantes, western France on August 26, 2014. This horse-dragon, created by the French artist Francois Delaroziere of “Les Machines de l'île” (The Machines of the Isle), is the hero of the show "Long Ma" which will be presented in Beijing on October 17, 2014 as part of the fiftieth anniversary of the relationship between France and China. (Photo by Jean-Sebastien Evrard/AFP Photo)

Simone Genziuk is one of the star’s of Sydney's Royal Easter Show – not surprising when you see her lift a 75kg washing machine with her hair. The 43-year-old known as Simi is one of the star’s of this year’s Royal Easter Show and it’s all thanks to her hair. Ms Genziuk is no newcomer to the art of circus performing having been an aerial acrobat for 13 years. (Photo by Nathan Edwards/Newspix/SIPA Press)

Kevin and Merith Starren have their picture taken by Merith's brother Mark Ernst (R) and nephew Logan Ernst (L) in front of a 50-foot snowman named “Granddaddy” in Gilman, Minnesota, March 6, 2014. (Photo by Eric Miller/Reuters)

American singer and songwriter Ava Max gestures as she arrives at the 2021 iHeartRadio Music Awards at Dolby Theatre in Los Angeles, California, U.S., May 27, 2021. (Photo by Mario Anzuoni/Reuters)

A bakery worker carries fresh bread in Cairo, Egypt on August 1, 2021. (Photo by Amr Abdallah Dalsh/Reuters)

Kim Kardashian west and Madonna backstage at MDNA SKIN hosts Madonna and Kim Kardashian West for a beauty conversation at YouTube Space LA on March 6, 2018 in Los Angeles, California. (Photo by Kevin Mazur/Getty Images for Madonna's MDNA SKIN)