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This level 5 expedition is one of our most challenging treks. Throughout the four days you will explore numerous caves, both river caves and dry caves; abseil inside Tu Lan Cave down to the underground river; climb plenty of steep hills, and trek through spectacular valleys. All the campsites are different as you move on each day to reach the biggest cave in the system Hang Tien. You will feel a real sense of achievement as you finally reach the road at the end of the fourth day.

  • Fascinating cave formations
  • Underground swimming
  • Abseiling in cave
  • Visit all 10 wet & dry caves
  • Stunning jungle campsites
  • Excellent food
  • Duration: 4 day tour
  • Tour type: Join-in; Private
  • Availability: Jan to Aug;
    Every Thur & Sun
  • Difficulty: Level 5 · Hard
  • Group size: Max 8 people;
    16 + years old
  • Distance: 30km trekking; 5km caving; 1km underground swimming; 150m elevation gain; 10m ladder climb; 15m abseiling


Due to the weather conditions the itinerary may need to be changed at short notice. The paths can be muddy and slippery after rain. Lifejackets must be worn when swimming in the caves.


You will be picked up from your hotel between 07:30 - 08:00 AM, for the an hour drive to Oxalis office in Tan Hoa, located 70 km from Phong Nha. Here you will have a tour briefing and prepare for the tour.


The trek starts with a flat path past peanut field and grazing buffalo and cows. A river crossing leads to a short but steep and rocky uphill section, followed by a corresponding downhill into the next valley. Cross the valley on a flat path to enjoy a picnic lunch in the entrance of Hung Ton Cave. More hills and jungle trekking before you drop down to Tu Lan Valley and your camp for the night.

Finish off the day with a swim into Ken Cave. Dinner is prepared and served by the porter team. After dinner enjoy chatting or card games before sleeping in your comfortable tent. Composting toilets are provided at camps.


The following day you will trek and swim through three caves; Tu Lan Cave, Kim Cave and Hung Ton Cave and do the underground abseil. After breakfast you will have a briefing and practice using the abseil equipment. From the campsite trek across the valley and into the dry entrance of Tu Lan Cave. Follow the well decorated dry passage to the end. Here the safety team will help you put on the abseil equipment. Enjoy the 15m abseil into the lower river passage with only your headlight for illumination. Our guide and safety team will assist you all the way. Land on the raft, and paddle out of the wet entrance.

Return to camp for a welcome lunch, and then trek around to Kim Cave. Enter the small entrance via a short climb, and follow the dry passage to meet the underground river. A series of short swims and waterfalls brings you to the beautiful To Mo Valley. Cross the valley and enter Hung Ton Cave next to the small waterfall. Swim along to the dry passage, where you will climb a metal ladder with the extra protection of a safety line. Follow the dry passage to the exit. The final hill of the day follows with a steep 150m climb and descent into the next valley of La Ken and camp. Enjoy your dinner after a long and challenging day.


The third day is a long trekking day over hills and through beautiful valleys and jungle. You will cover a total of 8km and around 350m of ascent. From camp you head uphill and trek through the jungle to Hung Nhai, a pleasant and mainly flat scenic valley. Lunch will be next to the river, before the last big hill of the day. Ascend and descend around 200m to arrive at a different river valley. A short trek upstream leads you to your camp site and welcome blue lagoon. Here the underground river wells up providing a cool natural swimming pool. Relax and enjoy this after your long hike.


The pace continues on the fourth and final day. After breakfast you will follow a very rocky trail to the entrance of Hang Tien, the largest cave in the Tu Lan System. Pass inside the spectacular entrance and proceed through the cave to the exit after a 10m ladder climb with safety rope. A short jungle section leads you to the second dry cave, with amazing rock patterns and cave formations. Return back the same way and enjoy a lunch break. The final challenge of the Expedition now follows; a 200m jungle ascent. Once you reach the top it is a relatively short easy descent to the road where you will be picked up with a welcome cold drink. Return to the office around 04:30 PM. Enjoy a welcome shower.


Enjoy breakfast at the hotel, take a swim in the pool at Chay Lap, or enjoy Chay Lap water sports center before leaving. Off-property excursions are available as well and can be booked directly through Chay Lap Farmstay.

Please contact our adventure consultant to be served and inform your departure time to your tour guide the night before to arrange transfer service. We wish you all the best in your onward travels!

Adventure Level 5: Hard

  • 4 day tour
  • Moderate to hard trekking- very rocky terrain
  • 30km of trekking including 5km of caving
  • Total elevation gain: 900m
  • River crossings
  • Swimming in caves (50-150m)
  • 15m underground abseil using ropes and harnesses (with instruction and supervision)

Frequently Asked Questions

  • What if I am a solo traveler, can I join a group?

    Solo travelers are most welcome and make up a large percentage of most groups.

  • Why do I have to sign your Release Form?

    We require customers to sign our Release Form to confirm they accept this is an adventure tour and they have to follow our guide’s instructions and safety rules. Customers also accept they have some responsibilities for their own safety.

  • I was wondering what the swimming is like in the trip? Will there be life jackets?

    It is true that you will swim up to 1 km on the Tu Lan Cave Encounter 2 days in 4 river caves. The shortest part is 70 m and the longest part is 250 m and all customers are required to wear a life-jacket while on tour due to safety purpose, regardless of swimming abilities. If you cannot swim at all but insist in doing the Tu Lan tour, your tour guide and safety assistant can assist you in the swim portions.


Please visit our FAQ general page to read our specific What to Bring list before departing for Vietnam and your cave expedition.


  • 1 night’s accommodation at Chay Lap Farmstay (single or twin-shared)
  • Camping gear: tent, camp light, sleeping bag, mattresses, pillow
  • Caving & safety gear: caving helmet, life jacket, gloves, safety harness, ropes..
  • Professional caving headlight (Hope Technology headlights – 1500 lumens)
  • Photography lighting supports (Hope Technology – R8 3,000 lumens)
  • Light PVC backpack (if you do not want to take your own, as it will get wet)
  • Dry bag (for clothing and personal belongings excl. electronics)
  • Basic canvas trekking boots (only if you do not have your own pair) sizes 36 – 46
  • Meals: picnic lunch and dinner (day 1, 2, 3 & 4), breakfast (day 2, 3, 4, and departure)
  • Gala dinner on day 4
  • Professional English-speaking tour guide and safety assistants
  • Porter team to carry all camping gear and prepare all meals
  • Porter team to carry all your personal belongings to camp
  • Shared dry box for phones and small cameras (limited availability for larger cameras)
  • Water purifier (used only by guide and porters) and water bottle
  • Basic camping facilities with eco-friendly compost toilet using western toilet seat
  • First Aid Kit and Medical Rescue Equipment (application by guides and porters only)
  • Secure Storage Facility at Oxalis Tan Hoa office to store all luggage you will not be taking on the trek
  • Transfer between Chay Lap Farmstay and Dong Hoi city center after tour
  • 1 hour complimentary kayaking at Chay Riverside


  • 2 long (easy to dry) pants and 2 long sleeved shirt to wear during the trek (quick dry)
  • 2 pair of shorts and t-shirts to wear at campsite and swim suit
  • 1 pair of trekking boots/shoes – difficult terrain, good footwear necessary. Gore-Tex/waterproof boots are NOT recommended as they do not drain well (if you prefer your own comfortable pair)
  • 1 pair of flip flops (sandals) for campsite
  • 1 medium size towel
  • 3-4 pairs of calf length densely woven socks (not ankle socks!)
  • Anti-fungal foot powder (talcum powder)
  • Personal items: mosquito repellent, sunglasses, hat, camera, underwear, toiletries
  • Shoe pads and thick socks if using Oxalis canvas trekking boots

Pricing and availability

Please choose your departure date using the calendar below to book your tour with us.

  • This tour is operated from January to August (closed from Sep to Dec.)
  • The days in bold are still available

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Whether you prefer long treks, camping in a cave, sleeping under the stars in the jungle, swimming underground in river caves, explore the huge dry caves or just taking an exploratory day trip, Oxalis Adventure Tours can provide the right amount of adventure just for you.

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