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)

Tiffany Porter of Britain falls after competing in the women's 100 metres hurdles final during the 15th IAAF World Championships at the National Stadium in Beijing, China August 28, 2015. (Photo by David Gray/Reuters)

Girl scouts pose for a group photo at the third station of the Way of the Cross reenactment marking Good Friday, in Port-au-Prince, Haiti, Friday, March 30, 2018. Thousands of Haitians are commemorating the crucifixion of Jesus Christ by reenacting the Way of the Cross, visiting the 14 stations, each marking an event that befell Jesus Christ on his final journey. (Photo by Dieu Nalio Chery/AP Photo)

Haitians dressed in costumes dance during the Haitian National Carnival in Jacmel, Haiti, 19 February 2017. Locals and foreigners gathered to enjoy the colorful carnival in which parades are full of art, music and dance. (Photo by Bahare Khodabande/EPA)

A military band prepares to play the national anthems before Cuban President Raul Castro welcomes U.S. President Barack Obama at the Palacio de la Revolucion in Havana March 21, 2016. Barack Obama on Sunday became the first US president in 88 years to visit Cuba, touching down in Havana for a landmark trip aimed at ending decades of Cold War animosity. (Photo by Jonathan Ernst/Reuters)

A protester is taken to hospital after he was wounded by birdshot during a street protest after it was announced that the runoff Jan. 24, presidential election had been postponed, in Port-au-Prince, Haiti, Friday, January 22, 2016. The Provisional Electoral Council in Haiti has postponed the election amid escalating protests by the opposition, which claims the first round was marred by fraud in favor of a government-backed candidate. (Photo by Dieu Nalio Chery/AP Photo)

Belgian model Stella Maxwell arrives for the screening of the film “The Idol” during the 76th edition of the Cannes Film Festival in Cannes, southern France, on May 22, 2023. (Photo by Sarah Meyssonnier/Reuters)

Voodoo pilgrims bathe in a waterfall believed to have purifying powers during the annual celebration in Saut d' Eau, Haiti, Saturday, July 16, 2016. Annually, the falls are the site of a large, important religious pilgrimage, during the festival of Our Lady of Carmel, from July 14–16. A Eucharistic rite is held during the festival, as well as various vodou rituals, but the penultimate devotional activity is bathing in the waters of the falls, and asking favors of the Virgin or Erzulie. After bathing, voodoo pilgrims throw away the dresses they wore to the site, and don new clothes for good luck. (Photo by Dieu Nalio Chery/AP Photo)