Cave system
Dragon's Breath Cave
End of the descending tunnel mapped by the SUNFISH vehicle in 2019. Some sources give 264 m without citation; the 2020 survey reports attach 265 m to Harasib Cave, not this lake. Divers have reached about 157-160 m (2024).
A cave on a private farm in northern Namibia that leads down to one of the largest known underground lakes. A 2019 robotic sonar survey traced it to about 205 m depth, and technical divers reached about 157-160 m in 2024.
Dragon's Breath Cave lies on private farmland at Harasib in the hills of northern Namibia, in the area between Otavi, Tsumeb and Grootfontein. Cavers first explored it in 1986. From a crevice at the surface a passage, including a tight squeeze and rope descents, drops roughly 50-60 m to the shore of a large underground lake.
The lake is unusually big for a cave lake: a sonar map made in 2019 put its surface area at about 2.6 hectares, and expedition reports call it the largest known underground lake outside glacial settings. Under the surface the floor slopes away into a wide descending tunnel.
In 2019 a team from Stone Aerospace mapped the lake with SUNFISH, an autonomous underwater vehicle that builds a three-dimensional sonar map and chooses its own route. It followed the tunnel, about 175 m wide and 60 m tall, for around half a kilometre until it ended at about 205 m. Popular articles often quote 264 m for this lake; that figure may come from the end of a chamber in nearby Harasib Cave, which the same expedition reported at about 265 m.
Human exploration has gone in stages. Before 2024 the deepest dive was probably about 132 m (2015). In June 2024 a German-led team, after years of preparation and with about 1.5-1.8 tonnes of equipment carried in, reached about 157-160 m on rebreathers in dives of nine hours or more.
The cave is on private land, and there is no public access. Dives here are expeditions arranged with the landowners.
Water, flow and flooding
The 2024 team reported water of about 25 C and visibility of around 100 m. The lake surface lies roughly 50-60 m below the entrance.
Why it matters
The lake is described in expedition reports as the largest known non-subglacial underground lake, and the leader of the 2019 SUNFISH survey described the robot as the first autonomous system to explore a completely unknown place inside the Earth.
Conditions
Water about 25 C and visibility around 100 m were reported by the 2024 team; no long-term measurements were found.
Typical ranges from published sources, not current conditions.
Survey and exploration history
| 1986 | Cavers first explored the cave. [1] [4] |
| 2015-07 | Divers reached probably 132 m, the deepest dive for the next nine years. [1] |
| 2019 | Stone Aerospace's SUNFISH autonomous vehicle mapped the lake and followed its tunnel to 205 m. [5] [4] [1] |
| 2024-06 | A German-led rebreather team reached about 157-160 m. [1] [6] |
Entrances and dive sites
One entrance is documented: a crevice on private farmland leading to a narrow squeeze and rope descents. It is not publicly accessible.
For orientation, not navigation. Hollow dots are approximate.
Every fact on this page, with its source (15)
| Fact | Status | Source |
|---|---|---|
| Dragon's Breath Cave is on private land at Harasib farm in the Otavi Triangle (Otavi-Tsumeb-Grootfontein) of northern Namibia. | Reported | [1] [2] |
| Wikipedia places the cave in the Otjozondjupa Region.Region from Wikipedia only (orientation). | Reported | [3] |
| Area-level coordinates rounded from the published location; the cave is on private land.Rounded to 0.1 degree on purpose. | Reported | [3] [1] |
| The cave was first explored by cavers in 1986. | Reported | [1] [4] |
| A 2019 survey with Stone Aerospace's SUNFISH autonomous vehicle followed a descending tunnel about 175 m wide and 60 m tall for about half a kilometre to its end at 205 m depth.Wikipedia also states 264 m 'below datum' without a citation; the 2020 reports give 265 m as the end of a chamber in nearby Harasib Cave, so the 264 m figure may refer to Harasib. | Sources conflict | [5] [4] [1] |
| The lake covers about 2.6 hectares according to the SUNFISH map.Wikipedia gives almost 2 hectares. | Sources conflict | [1] |
| The water surface lies roughly 50-60 m below the cave entrance.X-Ray Mag gives both figures in different places. | Reported | [1] [3] |
| The entrance is at about 1,550 m above sea level; another account places the plateau at 1,700 m. | Sources conflict | [2] [1] |
| The deepest dive before 2024 was probably 132 m, in July 2015. | Reported | [1] |
| In June 2024 a German-led team reached about 157-160 m on rebreathers, with dives of about nine hours. | Reported | [1] [6] |
| The 2024 team reported water of 25 C and visibility of about 100 m.Single expedition observation. | Reported | [2] |
| Access is through a surface crevice and a squeeze of about 60 by 40 cm, followed by rope descents. | Reported | [1] |
| Expedition reports describe the lake as the largest known non-subglacial underground lake.A Guinness listing is often cited in popular articles but was not checked. | Reported | [2] [1] |
| The 2019 expedition leader, Vickie Siegel, described SUNFISH as the first autonomous system to explore a completely unknown place inside the Earth. | Reported | [5] |
| The cave is on private land and the 2024 expedition was hosted by the farm owners; no public access exists. | Reported | [1] [2] [3] |
Verified: stated by an official or primary source we opened. Reported: from a secondary source only. Sources conflict: the note gives both versions. May be out of date: the newest source we found is old.
Written in our own words from the sources above. Report a correction