Son Doong Cave, or “mountain river cave,” is the largest known cave in the world. It’s located in the Quang Binh Province of Vietnam as part of the UNESCO-listed Phong Nha-Ke Bang National Park near the border of China.
The incredible scale of Son Doong Cave
Five miles long, the gargantuan cave stands 660 feet fall, 575 feet wide — making it larger than a 50-story New York skyscraper and then some! In fact, the cave is so large it hosts its own weather system and rainforest. It’s also home to various plants and 500+ vertebrates, including exotic animals like the flying fox.
A local man initially discovered the 450 million-year-old cave in 1991. But British explorers rediscovered it in 2009, making it one of the last unexplored parts of the Earth.
It opened up to boutique tourism in 2013, with the Saudi Arabian Crown Prince one of the first to visit the cave in 2014. The park allows only a few thousand visitors annually to help preserve its uniqueness and stunning beauty.
How Vietnam’s Son Doong Cave formed
The magnificent cave formed about 5 million years ago through the slow decay of limestone by continuous river water.
The ceiling collapsed, leaving gaping skylights and drips of water in the persistent 73 degrees Fahrenheit cave. The simulated rain created beautiful formations over thousands of years.
The Son Doon cave features downward-hanging stalactites and 10-story stalagmites, some of the world’s largest.