The sun-baked Kalahari Desert might seem like an unlikely location for a vast underground lake – and yet the Dragon’s Breath Cave, hidden in the remote Otjozondjupa region of Namibia, is thought to be home to the world’s largest.
The only clue to the cave’s existence is an inconspicuous hole in the ground, surrounded by craggy rocks and bushland, 46 kilometres north of the town of Grootfontein, that plunges into a vast flooded cavern 60 metres (196 feet) below.
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The cave gets its name from the warm, humid air rising from its entrance, which condenses into a fine mist in certain conditions, conjuring images of a dragon’s lair concealed deep below the surface. In reality, it was formed by karst dissolution – a geological process in which groundwater slowly eroded the region's soluble bedrock over millions of years, forming the massive water-filled void that exists today.
The cave was discovered in 1986 by South African explorer Roger Ellis during an expedition to the area. A year later, he returned to lead an expedition of cavers and divers from the South African Speleological Association to explore the cave further.
Navigating its complex series of drops, narrow ledges and vertical pitches, they found a lake at the bottom of the cave with a surface area of about 2 hectares (4.9 acres) – the equivalent of two football pitches.
In 2015, another major expedition succeeded in sending divers down to a depth of 132 metres – the limit of human endurance and technical diving at the time. However, the true depth of the cave remained a mystery until 2019, when Stone Aerospace arrived to map the cave with Sunfish, an autonomous, AI-powered underwater drone they had developed. Using multi-beam underwater mapping, they discovered the bottom of the lake is actually at a depth of 264 meters.
“We came to Namibia hoping to understand Dragon's Breath better,” said expedition leader Vickie Siegel at the time. “Sunfish is the first autonomous system to truly explore a totally unknown place inside the Earth.”
In 2023, another expedition achieved a new record when a team of divers descended to a depth of around 160 meters during a nine-hour-long dive, exploring a previously uncharted area of the cave network.
For anyone looking to explore the caves further, challenges include negotiating the cave’s steep shaft with heavy diving equipment to reach the water’s surface. Those who make it this far are then faced with braving the inky-black waters, extreme depths and hours of decompression required to resurface from the abyss.
Thanks to the cave’s unique conditions, with zero sunlight, crystal clear waters and stable temperatures, some unique and specialised aquatic species have made a home here.
These include the blind golden cave catfish (Clarias cavernicola), the rarest and most isolated fish in the world, along with sightless white prawns (Trogloleleupia dracospiritus), a small, endemic amphipod whose Latin name translates to “spirit of the dragon”.
These have uniquely evolved to thrive in the dark, still waters of the cave, living on the droppings (guano) of bats roosting in the upper reaches of the cave.
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Top image: Elmar Thiel, CC BY-SA 2.0 DE https://creativecommons.org/licenses/by-sa/2.0/de/deed.en, via Wikimedia Commons
