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 Bosnian special forces soldier returns fire 06 April 1992 downtown Sarajevo as he and civilians come under fire from Serbian snipers. The Serb extremists were shooting from the roof of a hotel at a peace demonstration of some of 30,000 people as fighting between Bosnian and Serb fighters escalated in the capital of Bosnia- Hercegovina. (Photo by Mike Persson/AFP Photo)

Coast and marine winner: Storm Gull (Lesser black-backed gull), New Haven, East Sussex. (Photo by Craig Denford/British Wildlife Photography Awards)

A camel is pictured in front of the Saturn tracking complex at the Russian-leased Baikonur cosmodrome in Kazakhstan on October 9, 2018. An astronaut and cosmonaut are due to travel to the ISS on October 11 aboard a Russian Soyuz MS-10 spacecraft from the Baikonur Cosmodrome in Kazakhstan. (Photo by Kirill Kudryavtsev/AFP Photo)

Chinese-American actress Bai Ling attends “The Key” screening at The Real Experimental Film Festival at Laemmle's Music Hall on November 21, 2014 in Beverly Hills, California. (Photo by Barry King/WireImage)

A plane flies past the moon in west London on Monday, January 17, 2022. The first full moon – the Wolf moon according to native north Americans – of 2022. (Photo by Victoria Jones/PA Images via Getty Images)

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)