Son Doong Cave Tour 2025 | Largest Cave Adventure

I’ve trekked Vietnam end-to-end, and reaching Phong Nha-Ke Bang National Park was a highlight. This UNESCO-listed wilderness (inscribed 2003) in central Vietnam is famed for its cave systems, including Son Doong - the world’s largest cave. Discovered by British explorers in 2009​, Son Doong finally opened to tourists in 2014. Now, only licensed companies like Oxalis Adventure can take visitors in. In this Son Doong Cave travel guide, I’ll share how to visit Son Doong, what to expect on the expedition, costs, gear to pack, plus insider tips and mistakes to avoid.

Getting to Phong Nha is the first step. From Ho Chi Minh City or Hanoi I took a train/bus to Dong Hoi and a short minivan ride to Phong Nha town, the gateway village. Phong Nha is right on the park’s edge​, and nearly all guesthouses and eateries are here. From this base you’ll meet your trekking crew and get final briefings. (Pro tip: Book a room in advance - accommodations fill up, especially during dry season.)
And in case the Son doong tour is too costly or just not available to book, don’t get disheartened. There are tons of Son doong alternative tours in Phong Nha from Massive Kong collapse (regarded as the most adventurous tour of Vietnam) to Tiger cave!

Booking & Permits

Only an Oxalis Son Doong tour is legit. You cannot do Son Doong as a DIY or day trip. Since 2014 the Vietnamese government has tightly controlled Son Doong visits, issuing only a few hundred permits per year​. Tours run roughly January through August (the dry season) - bookings open almost a year in advance and sell out fast. Expect to pay around US$3,000 per person for the 4-5 day expedition (Oxalis’ published rate is about VND 72 million, roughly $3000​ which can vary based on exchange rates). That includes park fees, guides, porters, meals, camping gear and caving equipment, so factor it into your budget. In peak season I heard Oxalis slots are gone a year ahead, so enquire early.

Group sizes on a Son Doong trek are small. Typically there are about 10-12 trekkers per trip plus a support team which can consist of more than 40 people, among them local porters, guides, cooks (So alongside the tourists you’ll be joined by a hefty crew making sure everything runs smoothly.) Flights or buses into Dong Hoi and a night in Phong Nha are easy to arrange with tour operators. Once booked, Oxalis will handle permits for you.

The Trekking Experience

Son Doong Cave map

The Son Doong tour is intense but incredible. Over 4 nights/5 days, you’ll hike through the jungle, camp under cave skylights, and explore massive caverns. The journey actually starts with Hang En Cave - the world’s third-largest cave. To reach Son Doong, adventurers must first pass through Hang En Cave, which is equally spectacular​. We camped on a white sand beach beside a freshwater pool - a surreal jungle campsite that was even used in the Peter Pan movie!​.

From Hang En, it’s a steep jungle trek. We hiked for half a day through thick forest (butterflies everywhere!), fording streams and even “many knee-deep rivers”​ before reaching Son Doong’s entrance. The cave mouth is at about 420m elevation - still tropical, but once you enter Son Doong the climate changes. Stepping inside the cave is jaw-dropping: You descend a fixed rope 80 meters down a sheer wall (“using harnesses and ropes”​) into an enormous chamber. The ground was rocky and often muddy, but awe took over as I stood in the dim light.

Expect gigantic spaces. Son Doong’s main hall is massive: over 5 km long, 200m high and 150m wide​. At one point we snapped a photo standing near collapsed dolines - a half-mile block of 40-story buildings could fit inside this lit stretch of Hang Son Doong​! In practical terms, you can camp under natural skylights (collapsed ceilings that let in daylight) in an otherworldly forest. Son Doong even has its own climate - it can be misty, and clouds of cool cave air billow out at dawn​. You’ll see high stalagmites (up to ~80m tall) and two collapsed sinkholes with daylight peeking through above​.

Evenings in the cave can be surprisingly cold (the average cave temp is around 21°C), so layers are necessary. At camp the guides set up Italian-style tents and meals; even the food in the cave was excellent thanks to the Oxalis team​. Despite the romance of camping underground, remember: you’re on a serious expedition. Plan to hike ~20-30 km total, carry a daypack, and use fixed ropes and ladders in places. You won’t touch any technical rock-climbing; everything is on a rope system provided by the tour. But you will be tired and sweaty (it’s hot and humid!). The ground (in the cave) was mostly wet, often slippery... another challenge was the humidity.

What to Pack

Packing well is key. Think camping + jungle gear: good hiking shoes or boots (they should allow wet use), a sun hat, quick-dry long-sleeve shirts and pants (to guard against sun and insects), and warm layers (fleece or down jacket) for the cool cave nights. A sturdy daypack (20-30L) to carry water, snacks, and rain gear is a must. Rain is unlikely underground, but the jungle trek to Hang En can be wet - a pack cover or dry bag is wise. Bring waterproof bags or liners to protect your camera and sleeping clothes from the constant drip of water​.

Also pack multiple headlamps and extra batteries. Although the tour provides lighting, you’ll still want your own backup. Sunscreen and insect repellent are crucial before you descend. Snacks like energy bars or nuts can supplement meals. Don’t forget a microfiber towel or cloth: in the cave everything gets damp, it is recommended to keep a dry microfiber cloth within reach as cameras and glasses can fog up​. Finally, personal items: carry any medication, comfortable hiking socks (plus spares), toiletries, and a lightweight sleeping bag liner if you sleep cold (though Oxalis provides sleeping bags and mats).

Son Doong Cave Tour - Tips & Mistakes to Avoid

• Book way in advance. Tours fill quickly. In 2023 Oxalis trips were sold out months ahead. Join the Oxalis Facebook group or email them early.

• Train physically. Expect daily hikes of 8 - 10 hours on uneven terrain, with a loaded pack. Practice hiking and stair-climbing, and build endurance.

• Don’t skip gear. Many travelers regretted not bringing enough warm clothes. Even in hot Vietnam, the cave nights are cool - pack a fleece or jacket. Waterproof cases or plastic liners saved phones and cameras from dripping water.

• Bring extra batteries/memory cards. You’ll want to capture these scenes. Electronics run out fast in the cold and humidity; a portable battery bank is useful.

• Trust the guides. Listen to your guides on rope descents and crossings. They are experienced (Oxalis guides have led dozens of expeditions​) and will keep you safe.

• Stay hydrated. Carry at least 2-3 liters of water and refill at campsites. The trek is hot and damp.

• Follow Leave No Trace. Everything you take in must come out. Stick to paths, don’t touch formations, and treat the cave as sacred. (Oxalis is very strict on this.)

• Be prepared for basic camping. There are no showers or flush toilets underground. Wet wipes, hand sanitizer, and a sense of adventure are must-haves.

• Enjoy the moment. Son Doong is surreal. Memories of camping under collapsed sky and walking among 40-story stalagmites will last a lifetime.

Nearby Wonders: Hang En and Other Phong Nha Caves

Your Son Doong trip comes with bonus sights. Beyond Hang En (see above), the Phong Nha-Ke Bang area has many caves worth exploring. In Phong Nha town you can book easier day tours to Phong Nha Cave (boat rides on an underground river) or Paradise Cave (vast dry cave with wooden walkways). Paradise Cave’s main chamber is about 31 km long - you can rent bikes to ride inside or walk its wooden path. (Phong Nha Cave is UNESCO-protected and reachable by boat with stalactites overhead.) There’s also the eerie Dark Cave (Hang Tối), where you mud-bathe and zipline. All these are great warm-ups or cooldowns around your Son Doong adventure.