The British-Vietnamese cave expedition team, working with local authorities and residents, conducted surveys in the park and its buffer zones from March 21 to April 11.
The team explored 29 caves in Quang Tri Province, including 26 previously unknown sites, many of which were assessed as having significant scientific value.
In the strictly protected zone of Phong Nha-Ke Bang National Park in Kim Dien Commune, the team discovered Cha Ngheo Cave, featuring a deep vertical shaft entrance and complex structure. The cave remains only partly surveyed, suggesting a larger cave system in the area.
Cha Ngheo is among the most difficult caves to access and is unsuitable for tourism. Preliminary measurements show it is about 583 metres long and 751 metres deep, with an almost sheer sinkhole entrance. The first flat section lies about 350 metres below the entrance.
Inside Cha Ngheo Cave is a high waterfall fed by a forest stream, cascading from the entrance into an underground stream below. The expedition team plans to return for further surveys.
In the Sinh Ton Valley area, the team identified the entrance to Thien Cung Cave as particularly significant, determining it to be part of the ancient flow route of the Hang Toi River within the park.
Thien Cung Cave stretches 4,206 metres, reaching up to 80 metres wide and 100 metres high in places. It contains striking stalactites, runs nearly parallel to the Hang Toi system and is hydrologically linked to the Chay River.
The team also explored Mo Roo Cave, a 515-metre mountain-piercing cave measuring 20 metres deep and 450 to 500 metres high, with underground streams and striking scenery.
Nuoc Lan Cave stretches 2,721 metres, is 10 metres deep and 152 metres high, and may carry seasonal water flow.
Ma Dom Cave stretches 1,257 metres and is 102 metres deep. Light filtering through its entrance creates bands of light and shadow, accentuating the interior and giving it a surreal quality.
Chac Den Cave stretches 468 metres and is 25 metres deep, with distinctive stalactite formations reflecting its geological development. Phong Nha-Ke Bang has recorded 472 caves spanning more than 254 km, making it home to one of the world’s richest cave systems.