Son Doong Underground Jungle Expedition Loop

Highlights

• Son Doong is the largest known cave in the world — its main chamber could hold a 40-story building.
• The expedition includes three nights camping inside the cave system, surrounded by underground jungle and river passages.
• Access is limited to 1,000 visitors per year, enforced through a strict permitting system managed by Oxalis Adventure.
• Two massive sinkholes allow sunlight to penetrate the cave, creating underground jungle ecosystems with their own weather patterns.
• The 6-day, 5-night format treats this as a genuine expedition, not a day tour.

Planning Steps

1. Book through Oxalis Adventure, the sole licensed operator for Son Doong Cave expeditions. Tours are fully booked through 2027 — plan at least two years ahead.
2. Complete the mandatory medical and fitness questionnaire. Oxalis reviews applications and reserves the right to decline participants who do not meet physical requirements.
3. Fly to Dong Hoi Airport (VDH) in Quang Binh province, Vietnam. Oxalis arranges pickup from Dong Hoi airport or train station.
4. Prepare physically for 25 km of jungle trekking, multiple river crossings, and scrambling with safety equipment. Prior multi-day trekking experience is required.
5. Arrive in Phong Nha one day before the expedition briefing at the Oxalis office. Use the extra day to explore smaller caves nearby.