ethan.brook News Editor
Massive Sinkhole Discovered in Phong Nha-Ke Bang National Park
A natural sinkhole with an estimated depth of 120 meters has been discovered and surveyed within the Phong Nha-Ke Bang National Park. Announced on October 22, 2026, by Director Le Luu Dung of Jungle Boss Company Limited, the enormous geological formation is located in the Chà Nòi – Khe Gát area.
The sinkhole features an oval-shaped opening measuring approximately 190 meters in length and 140 meters in width, covering a surface area of nearly 2 hectares—equivalent to about three standard football pitches. Dense tree canopies conceal much of the underlying geological structure from aerial views. The entire floor of the sinkhole is sheltered by a pristine primeval forest ecosystem containing numerous ancient trees according to findings released by expedition organizers.
Beneath the crater, the interior expands downward. It takes a shape resembling an inverted bowl. The space below extends to a length of about 250 meters and a width of 200 meters.
Expedition Teams Face Rugged Terrain
The location was initially identified through satellite imagery analysis directed by Le Luu Dung. Initial attempts to reach the site faced severe obstacles due to rugged terrain, sharp limestone mountain ranges, and scarce drinking water resources.
During an initial expedition in April 2025, a ten-member team including two forest rangers reached the upper rim of the sinkhole but had to turn back because of extreme terrain difficulties and depleted food and water supplies.
A larger, in-depth expedition took place from July 23 to 29, 2025, involving a 24-member team composed of cave experts from the National Speleological Society (NSS), Jungle Boss technical staff, and local forest rangers. The team trekked over 20 kilometers through the forest and across sharp limestone formations while managing limited water access. Using specialized rope access equipment provided by safety rigging systems, the expedition descended to the crater floor to conduct detailed measurements and ecological observations.
Researchers Document Geological Features
At the bottom of the sinkhole, researchers documented significant weathering on the central limestone foundation. This foundation features hundreds of small cracks and cavities that allow water to drain downward. Expedition members also uncovered piles of seashells, snail shells, and numerous monkey skeletons near the cliffs, alongside echoes of calling monkeys that indicate active wildlife presence.
Experts inspected the cliff walls for connections to underground cave networks, discovering a crack measuring roughly 5 meters high and 12 to 15 meters deep, though no airflow was detected. Kevin Ditamore noted that water drains through hundreds of tiny holes. It drains through minor crevices rather than concentrating at a single point.
Currently, we have not found an opening of significant size or any wind blowing up from the bottom of this sinkhole,
Kevin Ditamore stated. Lower cliff bases and drainage paths were buried entirely by rocks and soil from past landslides.
Following the survey, Jungle Boss submitted comprehensive field data to the Phong Nha-Ke Bang National Park Management Board. Jungle Boss also submitted reports to the board, proposing further scientific research in the Chà Nòi – Khe Gát sector and exploring new access routes from outside the sinkhole.