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)

Casey Stoner of Australia and Repsol Honda Team rounds the bend during the third day of MotoGP testing at Sepang Circuit on February 2, 2012 in Kuala Lumpur, Malaysia. (Photo by Mirco Lazzari gp/Getty Images)

Miss Panama Solaris Barba competes in the evening gown competition during the preliminary round of the 71st Miss Universe Beauty Pageant in New Orleans, Wednesday, January 11, 2023. (Photo by Gerald Herbert/AP Photo)

Eli Hanneman of Hawaii surfs in Heat 2 of the Round of 64 at the Ballito Pro on July 3, 2023 at Ballito, Kwazulu-Natal, South Africa. (Photo by Pierre Tostee/World Surf League via Getty Images)

Miss Seychelles Gabriella Gonthier walks through the crowd with fellow contestants for the start of the final round of the 71st Miss Universe Beauty Pageant in New Orleans Saturday, January 14, 2023. (Photo by Gerald Herbert/AP Photo)

Fans of Croatia are seen during the UEFA Euro 2020 Championship Round of 16 match between Croatia and Spain at Parken Stadium on June 28, 2021 in Copenhagen, Denmark. (Photo by Antonio Bronic/Reuters)

Jesus Taborda and Sabrina Amuchastegui compete in the final round of the Tango World Championship stage category, in Buenos Aires, Argentina, Saturday, September 25, 2021. (Photo by Natacha Pisarenko/AP Photo)

A fox runs out onto the pitch before the start of the second half. Celtic League 2012/13, Round 19, Leinster v Ulster, RDS, Ballsbridge, Dublin, March 30, 2013. (Photo by Paul Mohan)