Jungle Boss, a local adventure tour operator, said on October 23 that it had completed a survey of the previously unexplored sinkhole in the Cha Noi-Khe Gat area, working with the National Speleological Society of the United States and the park's management board.
The sinkhole was discovered in the Cha Noi - Khe Gat area of Phong Nha - Ke Bang National Park (Photo: Jungle Boss).
The expedition involved 24 people, including cave specialists, technical staff and local forest rangers. The team travelled more than 20km through dense forest and across sharp limestone formations to reach the sinkhole.
After setting up safety systems, the explorers descended ropes along a near-vertical rock face to a depth of 120 metres to measure the formation. Their findings showed that the sinkhole resembles an inverted bowl, widening towards the bottom.
The opening measures approximately 190 by 140 metres, while the interior is about 250 metres long and 200 metres wide, with a depth of 120 metres.
The opening is oval-shaped, measuring about 190m by 140m, while the interior spans roughly 250m in length, 200m in width and 120m in depth (Photo: Jungle Boss).
According to Jungle Boss, the first clue came from Kevin Ditamore, a veteran member of the US National Speleological Society, who spotted an unusually large dark patch while examining satellite images.
After three drone reconnaissance flights, Nguyen Van Uy, deputy director of Jungle Boss, and other specialists pinpointed the sinkhole. Uy said it was among the largest sinkholes he had encountered during more than 20 years exploring the forests of Phong Nha-Ke Bang.
The survey team found a thriving, largely undisturbed ecosystem at the bottom, including numerous large, old trees. The vegetation suggests that the formation may have existed for a very long time, although its age has not yet been scientifically established.
The explorers also found seashells and snail shells along the rock walls. Monkey calls were heard during the survey, indicating the presence of wildlife in the area.
The ecosystem inside the giant sinkhole (Photo: Jungle Boss).
The team also searched for geological clues that might lead to an underground cave system but found no promising route. The only feature identified was a narrow fissure measuring about five metres high and 12-15 metres deep.
Jungle Boss has submitted a detailed report and field measurements to the national park's management board, recommending further exploration of the Cha Noi-Khe Gat area and surveys of additional access routes from outside the sinkhole.
