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 woman carries an inflatable float with the sahpe of a portion of pizza in a Barcelona, on July 18, 2020. Four million residents of Barcelona have been urged to stay at home as virus cases rise, while EU leaders were set to meet again in Brussels, seeking to rescue Europe's economy from the ravages of the pandemic. (Photo by Josep Lago/AFP Photo)

A worker holds the head of a fox while killing it with electricity for its fur at a fox farm in Nanzhuang village, Shandong province, China, December 11, 2015. There are over 60 households in the village still raising foxes, raccoon dogs and other animals for the fur trade. China is the world's largest fur producer and exporter, according to state media. (Photo by William Hong/Reuters)

The Balance Bike Quad Eliminator being run (and organised) by GT Bicycles at the Malverns Classic, Start Line, Eastnor Deer Park, Eastnor, in Herefordshire on Friday 26th August 2022. Youngsters enjoy the thrills & spills of balance bike riding as they partake in the annual event held in rural Herefordshire. The thrills and spills as rider No. 013, Kelia Ranes tries hard to avoid a fallen competitor. (Photo by Richard Stanton/The Times)

Cosplayer Leah Panos as Snow White donates blood at San Diego Blood Bank on July 25, 2020 in San Diego, California. With the cancellation of 2020 Comic-Con International due to the coronavirus pandemic, the San Diego Blood Bank moved their 44th Annual Comic-Con's Robert A. Heinlein Blood Drive to encompass all of their locations and mobile units. (Photo by Daniel Knighton/Getty Images)

UK Love Island beauty Samira Mighty (L) seen arriving at Mahiki Kensington on November 16, 2018 in London, England. (Photo by CURLEY)

Boeing B-29 (#10) from the 24th Bomb Squadron, 6th Bomb Group after an emergency landing at Iwo Jima on April 24,1945. (Photo by U.S. Air Force)

Space shuttle Discovery sits atop NASA's 747 Shuttle Carrier Aircraft (SCA) ready to transport it from Kennedy Space Center to the Washington D.C., on April 17, 2012 in Cape Canaveral, Florida. Following the retirement of the shuttle fleet, Discovery will fly to Washington for display at the Smithsonian's National Air and Space Museum. (Photo by Lofty Ambitions)