The world's largest cave had been a hidden gem from millions of years until this farmer in Vietnam went hiking, saw the hole in the side of the mountain and decided to check out what he thought would be a cool cave. It is so much more than that, he stumbled upon the largest cave in the world. It's almost like a world of its own in there, of course there are caverns beautiful rock walls there's a rainforest, and even a beach. It's big enough to fit a 40-story skyscraper inside it and takes an entire week to walk through! Not only that, but it's estimated to be anywhere between 2 and 5 million years old. Check it out!
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