Son Doong, a cave in Vietnam's Phong Nha-Ke Bang National Park, has been recorded by Guinness World Records as the largest natural cave on Earth in the category of longest single cave passage, according to Podróże Gazeta.pl.
Vietnamese man Ho Khanh found the cave's entrance in 1990 while working in the park's forests and taking shelter from a heavy storm. He noticed mist pouring from a small opening hidden behind a rocky cliff and heard water flowing inside, but he did not explore further and later forgot the location. Cavers only rediscovered the site in 2009.
Massive scale
Son Doong stands about 200 meters high, 150 meters wide and at least 6.5 kilometers long. Its widest chamber, called Hope and Vision, is estimated to be tall enough to fit a skyscraper of more than 40 stories, and the outlet says the cave is wide enough to hold a Boeing 747.
Water, sunlight streaming through ceiling openings, and the cave's own microclimate have shaped an underground river and a forest inside, with mist resembling clouds drifting among the rocks. A network of underground rivers runs through the cave, and divers who tried to trace its full course could not reach the end, partly because they ran short of the gas needed for such a difficult dive.
In a section called the Garden of Eden, sunlight entering through a natural ceiling opening has allowed trees up to 50 meters tall to grow, along with mosses and ferns elsewhere in the cave. Cavers have reported seeing flying squirrels and snakes inside, and monkeys occasionally climb down in search of food.
