Bonito · Brazil · Cave & cavern · Freshwater
Abismo Anhumas
A 72 m rope descent onto a lake 80 m deep
Photo: Edmilson sanches · CC BY-SA 3.0
Abismo Anhumas is a cave lake under the limestone outside Bonito, reached by a 72 metre rope descent through a hole in the ground. The lake below is 80 metres deep and its surface is about the size of a football field; certified divers are guided to 18 metres over the submerged stone cones on its floor, and visitors without a certification get an 8 metre intro dive.
Also known as Anhumas Abyss.
Where it is and how deep
21.1531° S, 56.5988° WApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
The dive begins above ground, on the rope. You clip into an electric rappel rig at the mouth of the cave and drop 72 metres through the opening into the chamber below, coming to rest at the surface of the lake, and only then do you kit up and get in the water. The lake is 80 metres deep and its surface is roughly the size of a football field, so the scale of the room registers before any single feature in it.
What you have come to see stands on the floor of the chamber: submerged stalagmites, among the largest underwater formations of their kind anywhere, rising as much as 18 metres from the base. Certified divers are led to 18 metres over the cones, and visitors without a certification are taken down to 8 metres on an intro dive; there is also a snorkel float across the lake for anyone in the party who is not diving at all.
Marine life and season
The sources we used don't single out particular species here.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Good | Prime | Prime | Prime | Prime | Prime | Good | Good | Fair | Fair |
Season follows Bonito: The Apr–Sep dry season gives the most reliable clarity; heavy rain from Nov to Feb can cloud the rivers and close them for a day or two after storms.
Know before you go
- The only way in and out is a 72 m rope through a single opening in the cave roof, so the rappel, not the dive, is the part of the day that decides whether you can do it.
Photos from Abismo Anhumas
Lauro Sirgado · CC BY-SA 3.0
Dive videos
The Abyss : Diving the Abismo Anhumas, Bonito, Brazil · Trevor Coombs on YouTube
Sources
- Bonito, Mato Grosso do Sul — Wikipedia
- Bonito (Mato Grosso do Sul) — Wikipedia (DE)
- Abismo Anhumas — Abismo Anhumas
Photo credits
- Shaft of sunlight beaming down through the cave opening onto the turquoise lake inside Abismo Anhumas by Edmilson sanches, CC BY-SA 3.0, via Wikimedia Commons
- A single column of light cutting through the dark, cavernous chamber of Abismo Anhumas by Lauro Sirgado, CC BY-SA 3.0, via Wikimedia Commons
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