The Miao Room in China’s Gehibe Cave complex. Analyzed with a new laser tracking system, the expanse of this single chamber was recently measured at 380 million cubic feet, making it the world’s largest underground space. To put this in perspective, the single room is nine times the size of the old Houston Astrodome. You could fit four copies of the Great Pyramid of Giza inside it, and still have space for the Washington Monument.
1. The Miao room
Photos of the Miao Room show impossibly tiny looking people standing amidst 15-story tall stalagmites, walking among rocks which first appear to be pebbles, but are actually the size of houses. The vista looks like an “Empire of Rock,” or perhaps a stone Manhattan transferred indoors, complete with a major river system and skyscraper views. Using lasers, explorers mapped out a 3-D model of the cave in 2013, and after extensive data processing, announced their findings at the Hidden Earth conference in Great Britain, sort of a Super Bowl of the caving community.
Before fans of Miao can have their victory parade, there still remains some controversy over what really is the “world’s largest cave.” Here are the competitors.
2. The largest cave system
The Sarawak Chamber beneath the jungles of Borneo in Malaysia’s Gua Nasib Bagus (Good Luck Cave) previously held the official laser-measured title as the world’s largest single chamber. With measurements topping out at 377 feet high and 2,000 feet long, the room’s overall volume is only 10 percent smaller than that of Miao. But Sarawak’s surface area of 1.66 million square feet is larger than that of its Chinese competitor, with Malaysian partisans declaring that to make it the most super of the supercaves as it is the largest by that measure. Connected to 120 miles of chambers as part of the Clearwater Cave System, Sarawak is indeed super.
3. The longest cave
But wait, say fans of Kentucky’s Mammoth Cave, shouldn’t the world’s longest cave be considered the world’s true supercave? Mammoth’s 400 miles of passages are nearly double the length of its nearest competitor in the world’s longest cave ranking list, and explorers continue to find new passages, saying “there’s no end in sight.”
Unlike Miao and Sarawak, Mammoth is also super-accessible, with over 500,000 visitors touring the cave within the U.S. National Park each year. But don’t worry about crowds, there’s plenty of silent, dark space available — if all those people showed up on the same day, and you lined them up side-to-side, they still wouldn’t reach half-way through the passages.
4. The deepest caves
Since a cave is underground, perhaps the most proper measure of the greatest supercave should be the one that goes the deepest. For that, you must travel to the Republic of Georgia, where the Krubera Cave plunges at least 7,208 feet below the surface — that’s nearly one and a half miles. But as described in National Geographic’s Call of the Abyss, the path is far from straight down. Teams of explorers toting over a five tons of supplies attacked the challenge of setting a new underground record as if they were “climbing an inverted Mount Everest.” They spent weeks underground rappelling down freezing waterfalls and 500-foot cliffs, then using scuba gear to swim through underground lakes to explore water-filled passages leading to even lower chambers. Blocked by rocks, they used explosives to widen narrow passages before declaring a “temporary” halt at 7,200 feet.
Meanwhile, near Oaxaca Mexico, another team is exploring a series of passages in the Cheve cave network which have “only” reached 4,869 feet below ground, but radioactive dye they dropped into a cave stream reappeared over 8,000 feet below the mountaintop entrance to the cave, implying an even greater, super-deep discovery awaits.