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 visitor takes a selfie with a backdrop of sunflowers in full bloom at the E-World Sunflower Garden in Daegu, 237 kilometers southeast of Seoul, South Korea, 13 July 2024. (Photo by Yonhap/EPA)

Children react as a carnivorous theropod known as the Australovenator dinosaur walks through crowds along the Southbank, in London, Monday, February 18, 2013. The dinosaur is one of many that can be visited at the Erth's Dinosaur Petting Zoo, visiting from Australia, the creatures can be touched and fed at the Southbank Centre. (Photo by Kirsty Wigglesworth/AP Photo)

Supporters of the PHTK presidential candidate Jovenel Moise strike zombie poses during a protest march demanding the resignation of interim President Jocelerme Privert in Port-au-Prince, Haiti, Tuesday, June 7, 2016. The electoral council of Haiti has decided to re-do a presidential election that a special commission determined was marred by fraud. (Photo by Dieu Nalio Chery/AP Photo)

Members of the SubCielo company perform during the fifth annual Puerto Rico Circo Fest in San Juan, Puerto Rico, Saturday, March 10, 2018. The festival is held simultaneously in several spots on the streets of the Old San Juan city on March 10–11. (Photo by Ricardo Arduengo/AFP Photo)

A girl walks an Akita-inu dog dressed in a military uniform in Vladivostok, Russia on April 9, 2019. (Photo by Yuri Smityuk/TASS)

A mural painting by graffiti artist Eme Freethinker features likenesses of US President Donald Trump (R) and Chinese premier Xi Jinping wearing face covers in Berlin on April 28, 2020 amid the new coronavirus COVID-19 pandemic. (Photo by John Macdougall/AFP Photo)

An unidentified fashion lover waits outside Chanel's Haute Couture fashion show during snowfall in Paris, Tuesday January 22, 2019. (Photo by Thibault Camus/AP Photo)