The power of nature has quietly shaped the underground world with different expressions. When the unimaginable underground space is unveiled, people marvel at the magic of the world and the greatness of nature.


This article will introduce three of the world's mysterious and great caves.


1. Han Son Cave


Han Son Cave in Vietnam is by far the largest single large natural cave in the world and the largest cave passage in the world.


Its overall length reaches 8,855 meters and its height reaches 150 meters, which is equivalent to the height of a 40-story building, so its interior space is very large. Some say it can accommodate 7.2 billion people.


Han Son Cave has formed 300 million years ago. Because most of the mountains are limestone, such a large cave was gradually formed by the erosion and corrosion of the flowing water all year round.


There are many small caves hidden in the cave, at least 150 of which have been found so far, and almost all of them exist independently.


In addition, there are many lakes, rivers, and even small forests hidden in the caves. Occasionally, sunlight can penetrate through the small holes at the top. The scenery is pleasant and attracts many tourists every year.


It is said that it was first discovered by a Vietnamese farmer when he was sheltering from the rain. Because he encountered a storm in the mountains, he hurriedly found a cave to shelter from the rain and found this naturally formed karst cave.


The second discovery was in 2009 when a joint cave expedition team composed of the United Kingdom and Vietnam discovered the cave in the depths of the Vietnamese jungle. Since then, the title of the world's largest cave has been swept up by it.


2. Mammoth Cave


Mammoth Cave in Kentucky is the longest cave in the world. As of 2006, the length that has been explored is nearly 600 kilometers. It consists of 255 karst caves divided into five layers, which are connected from top to bottom.


There are also holes in the caves, which are like huge, tortuous, and deep underground labyrinths. Incredibly, as of 2013, Mammoth Cave is still expanding.


The origin of its name is also because of the large size of its cave, which is named after the ancient woolly giant mammoth. Legend has it that Mammoth Cave was stumbled upon in 1799 by a hunter named Robert Hochin while chasing a wounded wild bear.


3. Lexugula


Located in New Mexico, USA, "Lexiugula" has been named "the most beautiful underground cave in the world" by UNESCO because it has the most exotic mineral structure.


Lexugula is very different from the general cave. Its excavation does not rely on the erosion of water, but the slow erosion of sulfuric acid. The original limestone (CaCO3) reacts with sulfuric acid (H2SO4), eventually precipitating gypsum crystals.


They are transparent and crystal clear, like huge snowflakes covering the entire cave, and every place is a rare work of art.


But it's also because of these delicate and fragile crystals that Rexugula is the most regulated cave in the world. The BBC waited two full years for permission to film Earth Pulse.


This is also the last time the Reshukula cave management will allow entry, so this video will be the only way most people can enjoy unparalleled beauty.


After that, Lexiugula Cave will be restored to its most primitive state and will not be a spectacle of human destruction.