Son Doong cave is located in Vietnam close to the border of Laos. Found by a Vietnamese man named H?-Khanh in 1991 and made public by the British in 2009, Son Doong is the world’s largest cave. (Wikipedia actually describes it as “currently the biggest cave in world”, leaving room for speculation that there many be a larger undiscovered cave out there.) Son Doong’s largest chamber is over five kilometers (three miles) long, 200 meters (656 feet) high, and 150 meters (492 feet) wide. And that is only one chamber. Check it out:
Not exactly the dark, scary hole in the ground that you were expecting now is it?