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 pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

A Vietnamese cosplayer poses as police officer character from the game during the League of Legends (LOL) Mid-Season Invitational 2019 play-in group stage, in GG Stadium, Ho Chi Minh, Vietnam May 5, 2019. (Photo by Reuters/Kham)

Two hippopotamus are fed with pumpkins at the Hanoi Zoo, in Hanoi, Vietnam, 25 October 2018. The zoo has been the home for more than 800 animals of over 90 different species, including three hippopotamus, since it was built in 1976. (Photo by Luong Thai Linh/EPA/EFE)

“The western or lowland bongo is a herbivorous, mostly nocturnal forest ungulate and among the largest of the African forest antelope species. Bongos are characterised by a striking reddish-brown coat, black and white markings, white-yellow stripes and long slightly spiralled horns”. – Wikipedia

Photo: The one month old newborn Bongo Antelope Calf ventures out in the cold with his mother in their enclosure at London Zoo on December 9, 2005 in London, England. (Photo by Christopher Lee/Getty Images)

A Nepalese girl in traditional attire takes part in Kumari Puja, a mass worship ceremony for preteen girls, in Kathmandu, Nepal on September 27, 2023. In Nepal, Kumari Puja is the tradition of selecting a Kumari, usually a preadolescent girl, to worship symbolically as a goddess. More than hundred girls under the age of nine from across the country gathered for the mass worship. Performing Kumari Puja for three continuous years is believed to protect the girls from diseases throughout their entire life. (Photo by Narendra Shrestha/EPA/EFE)

Beachgoers are hit by a wave in La Libertad May 3, 2015. El Salvador emergency authorities declared a green alert along the pacific coats due to a large swell that affected the Salvadoran coast and originated from the extra-tropical storms that formed in New Zealand and the Southern hemisphere, according to El Salvador's ministry of environment and natural resources. (Photo by Jose Cabezas/Reuters)