The jungle is real here. A thick green mesh of seemingly impenetrable palms and brush and vines that dangle over a tight muddy path crossed by gnarling tree roots. Ahead is a gaping hole running up a mountainside, big enough to fit a 30-floor skyscraper standing upright. Inside, lime-green ferns cling to terraced formations built over hundreds and hundreds of thousands of years. And past it, the sandy path leads into a huge void. Going on almost feels like stepping into outer space.
This is Vietnam?
Yes. More specifically, it’s the new Vietnam. After all, Quang Binh Province, just north of Hue in Central Vietnam, was a mere blip on travelers’ radars even five years ago. Now it’s the fasting-rising destination in Southeast Asia.
The area is stunning, but the reason people are coming is the caves. They’re beautiful –— and really really big.
Phong Nha–Ke Bang National Park and the nearby Tu Lan system (both Unesco-protected) are home to the first-, third- and fourth-largest caves in the world. Dozens are available to visitors, with new opens opening each year (only 35% of the area has been explored as of yet). The world’s new cave capital has so many because of he reliable mix of heavy fall rains and pure limestone that dates 450 million years. Plus a few million years of time.
“It’s the perfect geology for caves,” says Howard Limbert, a British cave expert who has explored the area since 1992 and is responsible for opening many to tourism with Oxalis cave tours. “Straight away we knew it. This is the best area in the world for caves. They’re just so huge. We were amazed.”
Many outsiders know of Son Doong, the world’s largest, but truly it plays the “Mt Everest” to a whole Himalayas-worth of less strenuous, equally rewarding cave options. Some can be reached by motorbike or boat, with lit-up formations and walkways. Wilder, often grander, ones with underground rivers to swim or campsites inside involve strenuous jungle hikes to reach.
Here’s how to plan your trip, broken down by types of caves.
The easiest way to see some of Quang Binh’s geological subterranean wonder can more or less be done on your own or via organized tours too.
Paradise Cave, or Thien Duong, is 9 miles into the national park from the village. From the entrance, where you’ll find a dozen eateries, you can hike 15 minutes or take a golf cart to reach the ramp walk that switchbacks up a mountainside shrouded in jungle. At the top, steps lead through a narrow opening in the rocks and descend into the whopping 18 miles of caverns. Walkways access about three-quarters of a mile (some tours go deeper in), where you’ll see a staggering array of giant, lit-up stalactites and stalagmites.
To avoid (most) tour buses, be there when it opens at 7am. Entry is 250,000 VND (about US$11); the return ride on the golf cart is 100,000 VND (about US$4).
Also in the national park, the Dark Cave (named so for its lack of artificial light) is more about softball adventure than its geology. A guide joins you after you pay the 450,000VND (or US$20) entrance fee. You reach the cave by zip line over the river, then a short swim. You’ll pass a series off natural pools and calcified formations inside, capped with a narrow mud-filled passageway where you soak, neck-deep, before exiting for a short kayak ride an a drop into the river from zip line.
Phong Nha Cave, the world’s largest “wet cave,” is easiest to visit, as “dragon boats” go inside it directly from the market in Phong Nha village. It’s been used by locals for over a century – and served as a hospital during the Vietnam War – and became the first cave attraction for visitors in 1995.
Self-guided tours of its dramatic, lit-up formations take in only a portion of the cave’s five miles, though organized tours that venture deeper are available too. The boat is 360,000VND (US$16) for up to a dozen people; individual entry to the cave is another 150,000VND (US$6).
For about US$70 per person, a one-day tour offers the sweet spot for cave options for those wanting to go deeper and see caves in their natural state, yet still be back to your accommodation for a shower and dinner than night.
Elephant Cave & Ma Da Valley trek gets a little bit of everything. You get picked up at your accommodation in a Soviet-made transport vehicle from the Vietnam War, ride along the old Ho Chi Minh Road to start your trek in (and up) the thick jungle canopy. It’s a short hike up a steep path doused in vines to the opening of Elephant Cave. Inside you’ll find relics left by North Vietnamese soldiers who hid out here in the war — and a short dark hike past mammoth formations to the gaping exit of the cave.
The trek then follows the Ma Da Valley, where you wade knee-deep and take log bridges to criss-cross a clear-water river to reach a cliff-backed swimming hole for a dip and lunch. Then the trek toughens on a steep ascent and descent over a jumble of incredible limestone boulders to reach the “wet cave” of Tra Ang, where you put on life jackets and head torch and swim several hundred meters in the dark, as bats occasionally squeak above you.
For a really big cave, the excellent Hang Tien trek gives a taste of Tu Lan cave system, an hour ride’s north. You begin by listening out for flying foxes in the treetops as you make a sharp descent on a muddy trail to the gaping entrance of the cave that stretches up hundreds of feet. Lime-green moss clings to terraced limestone formations built over hundreds of thousands of years, if not more. Ahead, abyss.
The walk passes a series of unreal towering formations — one looks like a giant coiled snake — below a ceiling a few hundred feet above. Above you can see a groove, carved by an eddy of rainwater-fed river that incredibly fills this enormous space every fall. You hike back, stopping at a swimming hole for lunch, then climb back up out of the jungle — about six miles in all.
For a more historic cave experience, the Vo Nguyen Giap Cave, an hour south of Dong Hoi outside the national park area, just opened to visitors in January 2019. This author was the first American to ever venture into the site used but General Giap (who grew up nearby), and North Vietnamese soldiers, during the Vietnam War. You’ll visit an indigenous community, and two, sometimes cramped caves with some war-era construction in both to see.
For about US$240 and up (about 10% the cost of the four-day Son Doong trek), you can take a two-day trip. Trips include all food and camping supplies, and are usually near lovely swimming holes to rinse off the day’s grime.
One of the overnight highlights is Hang En, the gateway to Son Doong, and a huge attraction in its own right. It is the world’s third-largest cave after all — and a stunner, with a dramatic arch entrance, filled with swifts, that’s cut open from the lime green mountains.
You begin with a hard hike over jagged stones then lunch in an indigenous village only connected with the outside world by foot. You explore its colossal darkness with helmet’s torch lights, and the occasional beam of sunlight piercing the dark from unseen openings above. Porters bring all camping gear and food, and set up a campsite by an inside beach – as dramatic as it gets. Book through Oxalis.
One of the newest options, that sees even fewer visitors, is a two-day trek to see the world’s fourth-largest cave, Hang Pygmy, a “sister cave” of Son Doong, which opened to the public in 2018. The campsite is just inside the jungled opening to the cave.
THE BIG ONE: SON DOONG
A local accidentally discovered the opening to the world’s largest cave, Son Doong, in 1991, and in 2009, the British Cave Research Association, led by Howard Limbert, finally explored inside. It runs 5.5-miles (and counting – in April, British cavers discovered new depths) with subterranean jungle forests, entrances wide enough for jets to fly in (not advised), and inside caverns 300-feet tall. Four years later, tourists starting going in.
Trips aren’t for beginners — or the budget-conscious. The three-night trek (with two nights inside Son Doong) run US$3000 and are capped at 1000 visitors a year, max. It involves 15 miles of jungle trekking, often over jagged rocks, plus another 5.5 miles of caving involving rope climbs and scrambling up a 300-foot wall – and constant surprises, such as lunch at a minority village deep in the jungle, a night at Hang En’s cave beach (see above) or walks through surreal underground jungles of 100-foot trees and monkeys in the bottom of the cave’s sinkhole. Book through Oxalis.
When to go: Cave season lasts from mid December through August. Avoid the epic monsoon season (mid September through mid November), when cave tours are suspended and floods regularly fill villages and caves.
Tour operators: Local tour operators have exclusive access to many caves, so whom you go with depends on where you go. The clear stand-outs are Oxalis (the cave pioneer organization, who gets you to Son Doong and Hang En) and Jungle Boss (whose local guides have discovered many local caves themselves). Both are almost fully employed by locals, have detailed safety briefings and provide everything from water bottles, cooked meals on trail, transport and a helping hand on slippery bits.
Safety & concerns: You don’t have to have caving experience to do any of these tours, but you should mind the scope of the jungle trek. Five miles or more over limestone paths is quite strenuous, and it’ll be very hot. There may be log bridges to cross too, plus poison ivy to avoid and — full disclosure — a leech or two to flick off.
The sheer size of the caves means you won’t have to crawl or squeeze through tight chambers in most cases. Some caves are “dry,” where you’re scramble past and over giant formations, sometimes with ropes and safety harnesses. In “wet caves” you swim underground rivers! All tours provide helmets with torches and life jackets.
Read their trip descriptions (and packing list) carefully before making a decision right for you.