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 man walks along a corridor at a hotel in Singapore on February 7, 2024. (Photo by Edgar Su/Reuters)

17-year-old dance student Amelia Hubbard of Halesowen, West Midlands, takes to the park in south Birmingham, United Kingdom on April 14, 2022 to do some spring moves, as temperatures soar in the UK on Good Friday.(Photo by Peter Lopeman/Alamy Live News)

Storks casts shadows as they search for food on the dried-up Lake May in southwest Turkey on October 30, 2021. (Photo by Seyit Konyal/Solent News)

A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

Doesn’t taking a nap in a hammock outdoors sound lovely? Perhaps not when you’re hanging in the air, thousands of feet above ground, between two mountains in the Italian Alps! Which is exactly what these adventurous folks did during the International Highline Meeting in Monte Piana, Italy. (Photo by Sebastian Wahlhuetter Photography)

“My goal was to capture the image of a storm that emulated an atomic explosion”, Dobrowner says of this picture. Here: “Monsoon”, Lordsburg, N.M., 2010. (Photo by Roger Hill)

A protester wearing a bra and with a message written on her chest can be seen during the first of hundreds of womens' marches organized around the world in a show of disapproval of U.S. President Donald Trump in Sydney, Australia, January 21, 2017. (Photo by Dan Himbrechts/Reuters/AAP)