British geologists that the Miao Room, located in the Chinese province of Guizhou, is the world’s biggest cave chamber, with a volume of about 380.7 million cubic feet (10.78 million cubic meters). The new mapping of the Miao Room confirms that it’s about 10 percent larger in volume than the previous record holder, the Sarawak Chamber in Malaysia. The Sarawak remains the world’s largest cave by surface area at some 1.66 million square feet (154,500 square meters).
Originally discovered in 1989, the Miao Room is part of the immense Gebihe cave system underneath China’s Ziyun Getu He Chuandong National Park. Explorers already knew it was extraordinary—the cave could hold approximately four replicas of the Great Pyramid of Giza—but in 2013, a new mapping of the cave took place under the auspices of China’s Institute of Karst Geology.
To conduct the survey, the team—in a first for cavers—took advantage of a Riegl VZ-400, an architecturally minded measuring apparatus, . Consisting of a metal cylinder (not including its batteries and necessary laptop and cables), the device spins 360 degrees and takes up to 122,000 measurements per second. Data from the device was then reprocessed by researchers at the University of Lancaster in the UK. Their findings were announced at the Hidden Earth 2014 national caving conference, held in England over the weekend of September 26.
“To me, this is like discovering that K2 is larger than Everest!” Tim Allen, a leader of the expedition, told National Geographic this week.