Planning a trip to Vietnam and keen to explore some of its most spectacular scenery? A little north of the 17th parallel – the demarcation where Vietnam was once divided into north and south – lies Phong Nha-Ke Bang: 885 square kilometres of unspoilt jungle, caves and underground rivers squeezed between the Laos border and South China Sea.

The UNESCO-listed national park hit the headlines in 2009, when its colossal Hang Son Doong (Son Doong Cave) was discovered to be the largest in the world, and again this year, when the rugged terrain was used as a location for Hollywood blockbuster Kong: Skull Island. But the region is changing fast, with improving transport links bringing in more tourists than ever.

Here’s why you should go now, plus everything you need to know to plan your trip:

Phong Nha is famous for its caves, right?

The stunning 400-million-year-old limestone karst landscape is littered with caves and underground rivers – and every year more are being discovered, surveyed and opened to the public. At more than 5km long, and comfortably able to fit a New York City block within its expanse, Son Doong Cave is the best known.

If you have a spare US$3000 you can try and bag a place on the five-day expedition that Oxalis organise to its remote location. There’s also talk of a planned cable car that will ferry thousands of people to the entrance. This will detract from the feeling of discovering a lost world, though, so if that’s what you’re hankering after, best visit sooner rather than later.

With a little less cash and advanced planning, you can visit beautiful Phong Nha Cave, which is closest to Phong Nha town and only accessible by dragon boat from the little jetty here. Dark Cave (Hang Toi) involves a zip line, a muddy exploration, a cold swim and a short kayak trip, while Paradise Cave is a huge dry cavern with a deceptively tiny entrance. The latter has mind-blowing stalactite and stalagmite formations, which can be viewed from a boardwalk. Other caverns, such as Hang Va and Hang En, require some demanding trekking.

Phong Nha Cave, VietnamMr and Mrs Backpacker/Flickr

OK, so there are caves. What else?

Phong Nha’s incredible biodiversity includes globally threatened large-antlered muntjacs, langurs, macaques and Asian black bears, not to mention hundreds of species of birds, reptiles and amphibians. Only a fraction of the park is open to tourists, but it’s free to enter – you only pay for the specific attractions – and phenomenal views open across the rugged landscape from the 65km loop via Highway 20 and the Ho Chi Minh Trail. The botanical gardens are 12km from town and you can explore on foot, scrambling down to Gio Waterfall for a dip.

There’s also the entrance of the Eight Ladies’ Cave to visit. Here, a temple honours the eight young locals who, in 1972, were trapped and entombed during an American bombing raid. The whole area was devastated during the Vietnam War (look out for the craters still dotting the countryside), and because there is still unexploded ordnance in the park, independent trekking is prohibited here.

Local operators Oxalis and Jungle Boss organise some intrepid multi-day treks in the jungle, where you sleep under canvas or in a minority village.

Monkey in Vietnam national parkPixabay/CC0

And outside the park?

Getting off the tourist trail and exploring the rice paddy farms and rural villages by bicycle is a joy; don’t miss Bong Lai Valley, which feels like the Vietnam of ten years ago. Bump along the dirt roads to visit The Duck Stop where friendly host Quynh will show you round his family’s pepper plantation.

Rice terraces in VietnamPixabay/CC0

I’m sold. How do I get there and where do I sleep?

Phong Nha is increasingly on the traveller’s radar and the small town of the same name is now a drop-off point on tour buses. If you don’t fancy the sleeper bus from Hanoi (10hr) you can take a bus or train to nearby Dong Hoi and take a taxi or the hourly local bus to Phong Nha Town (45km).

Phong Nha Town

Phong Nha Town (sometimes known as Son Trach) has one length of road that has recently developed into a bustling centre for the Phong Nha-Ke Bang National Park. Backpackers are well catered for here, with Easy Tiger hostel at the centre of everything – there’s a free information talk at 9am every day. Plenty of simple accommodation is also available in town, and you can stroll up and down to check a few rooms.

Farmstay Village and around

Rural villages surround Phong Nha Town and it’s easy to find a homestay. Grab a map and head to Farmstay Village where accommodation is well signposted, but be aware that homestays (usually around $10 a night) are fairly basic and not much English is spoken. For a little more luxury, Phong Nha Farmstay has the same peaceful rustic setting, but with a pool and restaurant.

Phong Nha farm stay in Vietnam, Southeast AsiaVT Polywoda/Flickr

Dong Hoi

This is where the nearest airport and train station is, 50km from the park – but don’t be fooled into thinking that the city of Dong Hoi is just a transport hub. Quietly engaging and particularly lovely where the Nhat Le River meets the sea, you could stay here and take day-time forays into the park. Sitting right on the beach is Beachside Backpackers and there are some gorgeous cafés and restaurants along the riverfront.

Dong Hoi, VietnamKaj17/Flickr