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)

Waves batter the North Devon coast at Ilfracombe, UK on August 23, 2024, as Storm Lilian hits the UK and the Met Office issues a yellow weather warning. (Photo by Mark Passmore Photography)

Residents ride on top of an overcrowded “Jeepney”, a locally manufactured public transport, along a highway in Mogpog town on Marinduque island in central Philippines April 8, 2015. (Photo by Erik De Castro/Reuters)

Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. Brazilian revelers traditionally dress in white to honor the New Year's holiday along with the Brazilian Goddess of the Sea- Iemanja. (Photo by Mario Tama/Getty Images)

People spray water in the street ahead of “Songkran”, the annual Thai New Year water-throwing festival, in Kowloon City, Hong Kong, China, 09 April 2017. The pouring of water is a key element in the festival as it represents purification and the washing away of one's sins and bad luck for the year. The event also includes a “Miss Songkran” pageant where contestants are clothed in traditional Thai dress, and a winner is crowned. This year's “Songkran” will begin in Thailand on 13 April 2017. (Photo by Alex Hofford/EPA)

An Indian nomadic Gujjar girl hangs on to a horse cart after collecting bricks from debris on the outskirts of Jammu, India, Tuesday, March 7, 2017. The Gujjar tribal communities are considered by some to be economically and socially backward and the lack of care by the state government has led to resentment amongst the community. The tribe moves to the plains from the hills to escape the cold winters. (Photo by Channi Anand/AP Photo)

Tigray refugees who fled the conflict in the Ethiopia's Tigray ride a bus going to the Village 8 temporary shelter, near the Sudan-Ethiopia border, in Hamdayet, eastern Sudan, Tuesday, December 1, 2020. (Photo by Nariman El-Mofty/AP Photo)

Two displaced Tigrayan girls giggle next to their mother, left, as their photograph is taken outside the Hadnet General Secondary School which has become a makeshift home to thousands displaced by the conflict, in Mekele, in the Tigray region of northern Ethiopia Wednesday, May 5, 2021. The Tigray conflict has displaced more than 1 million people, the International Organization for Migration reported in April, and the numbers continue to rise. (Photo by Ben Curtis/AP Photo)