Vietnam’s Massive Cave Now Open For Tours! 

No one had seen anything like Son Doong cave until 1991, when a man named Ho Khanh happened upon its entrance in the Vietnam jungle. Due to the sound of a roaring river and the sheer drop into the darkness, the interior of the cave wasn’t glimpsed by human eyes until 2009 on a British Cave Research Association expedition. What they found was a cave that was not just five times larger than the previous largest cave in Vietnam, but twice as massive as Deer Cave in Malaysia, the record holder for world’s largest cave. Rappelling into the cave (via Oxalis)

Now, tours for the public are being organized organized for the first time through operator Oxalis. The first adventurers spent nearly a week journeying to Son Doong and camping inside the cave in August, and the plan is for the tours to be held annually between February and August. The cave is 5.5 miles long, and includes a whole roaring river, stalagmites that tower up to 260 feet, geological formations that look like surreal land art, wide sinkholes, rare rock structures called cave pearls, fossils as old as 300 million years, and even a jungle with trees growing to nearly 100 feet where flying foxes, monkeys, and hornbills roam.

Keep reading about how the world’s largest cave is now open to intrepid travelers, on Atlas Obscura!