Phong Nha–Ke Bang: caves you can walk into, and caves you cannot

Phong Nha–Ke Bang National Park was established in December 2001 and enlarged in 2013 to 123,326 hectares. UNESCO inscribed it as a World Heritage site in 2003 for its geology and landforms, and in 2015 extended the listing to cover its ecological processes and biodiversity. In 2025 the listing became a transboundary site with Hin Nam No National Park across the border in Laos, and in June 2026 the area was named a UNESCO World Biosphere Reserve.

On the ground, that means a large block of forested karst cut by rivers, with a small tourist town, Phong Nha, on the Son River at its eastern edge. The two caves most visitors see are a short distance from town and are run as mass-tourism sites, with ticket counters, boats and lit paths. Beyond them the park becomes a place of guided treks and camping, and the facts change accordingly: group sizes are small, places are limited and fitness matters.

Since 1 July 2025 the area belongs to Quang Tri province, after Quang Binh was merged into it. Signage, tickets and older guides may still say Quang Binh.

Guinness World Records lists Hang Son Doong as the largest cave, at around 200 metres high and 150 metres wide, with a length of at least 6.5 kilometres; later surveys put the total at about nine kilometres. A local man, Ho Khanh, found the entrance in 1990, and British cavers surveyed it in 2009. Tourist expeditions began in 2013.

Access is narrow. A single operator holds the permit, the cave takes expeditions from January to August only, and groups are limited to ten visitors supported by about thirty staff. In March 2026 a state news outlet reported that all places for 2026 and 2027 were booked and that the price was close to VND 80 million per person. Applicants have to pass a theory and a practical fitness test.

The tourism authority describes October to December as the rainy season, when many caves cannot be reached, and suggests going at other times. The UK Foreign Office gives October to December as the rain season for central Vietnam, with seasonal flooding in October and November. River caves such as Phong Nha Cave depend on the boat route being safe; Paradise Cave sits higher and does not flood the same way, but trails around it turn slippery.

From January the caves reopen gradually and the expedition season starts. Hang Va is at its fullest from January to March. Spring and summer are the main season; summer is hot outside the caves, which stay around 20 to 22°C inside.

These prices come from a commercial operator's published list and a state news report; we could not find a dated schedule from the management board. Treat them as a range and check before you go. We do not publish hotel prices for Phong Nha.

• Anyone travelling in October to December who wants river caves or treks: the rains close many of them.
• People who cannot manage several hundred steps or long stretches on uneven, damp ground; even the walk-in caves involve both.
• Travellers who want Son Doong next year without a booking: the places were reported taken to the end of 2027.
• Anyone outside the 40–90 kg range who wants the Hang Toi zip line.
• Visitors with only one night and no flight into Dong Hoi: the travel time outweighs the caves.