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)

Actress Tang Wei poses at the “Wu Xia” portrait session during the 64th Annual Cannes Film Festival on May 15, 2011 in Cannes, France. (Photo by Andreas Rentz/Getty Images)

Costumed revellers perform in the parade during the Notting Hill Carnival in London, Monday, August 27, 2018. The carnival has been held every year since 1966 and one of the largest festival celebrations of its kind in Europe. (Photo by Tim Ireland/AP Photo)

Actress and model Charlotte McKinney attends the grand opening of NightSwim at Encore Beach Club at Wynn Las Vegas on May 5, 2017 in Las Vegas, Nevada. (Photo by David Becker/Getty Images for Wynn Las Vegas)

Model Ashley Graham is seen walking in Soho on May 9, 2017 in New York City. (Photo by Raymond Hall/GC Images)

Eleonora Brunacci and Mariano Di Vaio walk the red carpet ahead of the “Racer And The Jailbird (Le Fidele)” screening during the 74th Venice Film Festival at Sala Grande on September 8, 2017 in Venice, Italy. (Photo by Pascal Le Segretain/Getty Images)

People take part in the annual LGBTQ Pride parade in Bangkok, Thailand on June 4, 2023. (Photo by Athit Perawongmetha/Reuters)