Hang Cha Ngheo: 583-metre sinkhole cave with waterfall found in Phong Nha-Ke Bang

April 20, 2026 | Phong Nha, Quang Tri Province

Twenty-four new caves in a single expedition season. That's what the British-Vietnamese caving team just pulled off in Phong Nha-Ke Bang National Park, and one of them is getting a lot of attention.

It's called Hang Cha Ngheo. A sinkhole cave, 583 metres long, 45 metres deep, sitting at 751 metres elevation in Kim Dien commune inside the national park. The entrance drops almost straight down into an underground stream, and there's a waterfall running through the interior. The Phong Nha-Ke Bang National Park management board announced the find on the evening of April 20th.

The cave hasn't been fully explored. The area around it shows potential for a larger connected cave system, and the cave itself is still geologically active, still forming. Full results from the entire expedition season, which also added survey data to three previously known caves, are expected by the end of April.

Note: Image source of Hang Cha Ngheo - https://vnexpress.net/quang-tri-phat-hien-hang-dong-dang-ho-sut-co-thac-nuoc-dai-gan-600-m-5064855.html

How it sits alongside Son Doong Cave

Comparing Cha Ngheo to Son Doong is a bit like comparing a well to a cathedral. Son Doong is a horizontal passage, nearly 9 kilometres long, with a volume of 38.5 million cubic metres and ceilings that reach 200 metres. You could fit a 40-storey building inside it. Cha Ngheo drops vertically, 45 metres down into darkness, with water pouring through it.

What they share is context. Both sit inside Phong Nha-Ke Bang and both were found by British-Vietnamese expedition teams in terrain that nobody had properly surveyed. And we don't have full dimension data on Cha Ngheo yet, so the real scale of this new Phong Nha cave cave is still unknown.

Son Doong itself wasn't found until 1991, when a local man named Ho Khanh walked into the entrance during a rainstorm, heard wind and water rushing below, and couldn't get past the drop and interestingly he lost the location coming back which remained lost for 18 years. Howard Limbert and the British Cave Research Association finally surveyed it in 2009, with Ho Khanh guiding them back. The cave turned out to be so large it has its own cloud systems and a jungle growing inside it that the teams started calling it the "Garden of Eden."

If that could go unnoticed until 2009, a 583-metre sinkhole with a waterfall sitting undiscovered in 2026 shouldn't surprise anyone.

Phong Nha-Ke Bang has over 500 known caves. It keeps finding more.

Crossing the slackline at Kong Collapse, one of the deepest sinkholes on Earth, on the Tiger Cave Series route through Phong Nha-Ke Bang.

The region sits on continuous limestone with very few geological faults, which is exactly the kind of formation that produces massive cave systems over millions of years. Around 40 caves are currently open for tourism, including Son Doong Cave (largest in the world), Hang En (third largest), and Hang Pygmy Cave (fourth largest).

And sinkholes are not rare here. Anyone who has done the Tiger Cave Series expedition through the park knows this already. Kong Collapse, which is part of that route, is considered one of the deepest sinkholes on Earth. You reach it by swimming 300 metres through a dark cave where you camp at the bottom overnight. Between Over Cave and Hang Pygmy Cave there's another sinkhole with a primeval forest growing inside it. You walk straight through it on Day 2 of the trek.

We run the Tiger Cave Series at Jungle Boss Tours, so we see these formations regularly. Cha Ngheo could be something genuinely significant, but until the full survey is published, all we really have are the basic measurements and the knowledge that there's a waterfall down there that the expedition team couldn't fully reach.

That's what keeps this region interesting. Over 500 caves documented, decades of exploration by some of the best caving teams in the world, and they're still pulling 24 new ones out of the limestone in a single month.

Jungle Boss Tours is based in Phong Nha and operates caving and trekking expeditions through Phong Nha-Ke Bang National Park, including the Tiger Cave Series, Hang Pygmy Cave, and Hung Thoong. For more information, visit our Phong Nha tours page or get in touch with our team.