Phong Nha-Ke Bang
Phong Nha is fast becoming well known as one of the most beautiful areas of Vietnam. The Phong Nha Farmstay in 8km south of Phong Nha, deep in the Vietnamese countryside overlooking rice paddies, and is situated to easily explore the area. The area is new to tourism, so there isn’t much choice of eateries, shops or transport. It is expanding however month by month. Coming to Phong Nha really does provide a chance to get out in the real Vietnam on a bicycle or walking and soak it up.
Flora and fauna
Currently, the closest service is via Vietnam Airlines to Dong Hoi, check their website for latest fares and flight times.
Several arrivals and departures at Dong Hoi daily from as far away as Hanoi and Ho Chi Minh City, only a few hours from Hue.
DMZ Transfer Bus leaves Phong Nha daily to and from Hue Backpackers. This bus stops in both directions at the Ben Hai River Museum where the country was divided throughout the American War. It also stops at and includes a tour guide to explore the Vinh Moc Tunnels just above the DMZ. The cost for this trip is 500,000VND per person and tickets are available at Hue Backpackers in the South and Easy Tiger, Phong Nha Lakehouse, Pepperhouse and Phong Nha Farmstay. The Timetable is
Easy Tiger Phong Nha 6:30am
Pepperhouse Homestay 6:45am
Phong Nha Farmstay 7:00am
Vinh Moc Tunnels 9:00am
Ben Hai River Museum 11:00am
Dong Ha 11:30am
Hue Backpackers in 12:30pm (Pham Ngu Lao St, Hue)
Hue Backpackers in 1:00pm (Pham Ngu Lao St, Hue)
Dong Ha 2:00pm
Ben Hai River Museum 2:30pm
Vinh Moc Tunnels 3:15pm
Phong Nha Farmstay 6:00pm
Pepperhouse Homestay 6:15pm
Easy Tiger Phong Nha 6:30pm
There is also a local bus from Hue to Phong Nha leaving from Northern bus station in Hue. One of the buses leave around 10:30. If coming from Hue and don't want to book any tour, then this is the best (and cheapest) option to get to Phong Nha. Hotels or travel agencies are not willing to tell about this bus in Hue. If you are staying in homestay or guest house along the highway close to Phong Nha, the bus can drop you there if requested.
Motorbikes can be rented for 150,000 VND from hotels in Dong Hoi. It takes about 1 hour via a highway that has little traffic: the Phong Nha cave is about 45 km from Dong Hoi and the Thien Duong (Paradise) Cave is about 70 km from Don Hoi.
Pickups from Airport, Train Station, or Tourist and Local Buses to and from Ha Noi can be arranged for around 500,000VND through the reputable hotels and accommodations in Son Trach (Phong Nha) and Cu Nam.
Taxis can be hired from hotels/resorts, airport or train station in Dong Hoi. About 1 hour on a highway with cars, oxcarts, motorbikes, buses, trucks.
Tours are available from both Easy Tiger Hostel at Phong Nha and Phong Nha Farmstay in Cu Nam Hue.
Hotels in Dong Hoi can arrange day trips to the park but best to stay out there as Dong Hoi is 50km away.
The National Park was opened to the public a just over 2 of years ago, and consists of pristine untouched jungle spread throughout a rugged landscape. The area is full of large cave systems, the most famous being the Paradise Cave, Hang En cave and Phong Nha Cave. Last year it was announced that a new cave had been discovered that is the largest in the world – The Son Doong cave. Oxalis Adventure Tours opened it up to tourism in August 2013 with a six day exploration costing 3000USD per person .
The Phong Nha Ke Bang National Park is not very 'open' as yet. The area is close to the Laos Border, the military has a presence within the park, and the park has one of the highest concentrations of unexploded ordinance (bombs) in the world. Currently, you are not allowed to hike or trek through the park without a licensed tour operator, and most of the hiking is found as part of caving expeditions, such as to Hang En. There are 2 roads that travel through the park, the Ho Chi Minh West Highway, and Highway 20 (otherwise known as 'Victory Road'), and these create a loop which can be traveled by scooter or on a tour.
Phong Nha and Tien Son Caves: It costs 80,000 VND to visit the Phong Nha cave and 40,000 VND to visit the Tien Son cave(120,000 VND for both) and 320,000 VND to rent a boat for up to 14 people to visit one or both caves. (prices as of March 2014) You can share a boat with other tourists that show up. Renting a boat is a requirement as there is no other way to get to the caves. Caves are exquisite and very large. It is about 45 km by road from Dong Hoi and takes about an hour by motorbike. Or call direction to Phong Nha tourism (tourism manage organization) to book the ticket: 
Nuoc Mooc Spring Eco Trail: 50,000 VND for ticket. Transportation can be negotiated to take you there from Phong Nha village. Buy ticket at the hut under the sign off the road, then wander the bamboo bridges and paths along both sides of the river/rapids. Go back to see where the river springs up out of the ground. This is also on the road to the Thien Duong (Paradise) Cave.
Thien Duong (Paradise) Cave: Newly paved road off the main HCM Highway provides car/motorbike/bus access. Buy 120,000 VND ticket to enter; the fee includes an English speaking guide. Just after that, separate >>optional<< ticket for non-polluting electric golf cart to the base of the stairs (if nice weather, walk along the new path of about 1.6 km instead). Approx. 500 stairs up to entrance of cave, another 100-200 stairs down inside. Stunning, tastefully lit cave features along 1.1 km of new (spring 2011) wooden pathways. It is about 70 km by road from Dong Hoi and takes about an hour and a half by motorbike. Some claim that this is among the most beautiful caves in the world.
Tu Lan Cave System, (About 40km from Phong Nha). One of the most beautiful untouched areas of Vietnam showcasing minority cultures amongst real jungle, rivers and waterfalls. There are currently 10 known caves in Tu Lan sitting untouched for thousands of years. A special permit is required to visit this area which is only available through local responsible tourism operator - Oxalis Caving Tours. This area is ripe for exploring with plenty of underground rivers and waterfalls! Tu Lan is the Ha Long Bay of Central Vietnam hidden amongst the mountains! edit
Hang En is of the largest and most beautiful caves in the world, this is close to Hang Son Doong (the world's biggest cave). To see this cave involves a day trek through beautiful jungle and valleys, and through a minority village, and then an overnight stay in the cave. Tours can be arranged at Easy Tiger in Son Trach or Phong Nha Farmstay in Cu Nam.
Hang Son Doong is the world's biggest cave, discovered as recently as 2009. A cave so big that a whole Manhattan city block, skyscrapers and all, could fit inside of it. Tours started going to it this year, and numbers are restricted to only 84 tourists/year. There are a few spaces available next year on the 7 day trek to the cave, at the price of $3000/person.
Some Tour and Activity Options at Phong Nha.
Please note: Many of the caving tours are very weather dependent, so please enquire before booking. The Farmstay National Park tour almost always runs. However the 7km Paradise cave trek and the Hang En cave trek is often unavailable, especially during the winter months (October – December). The Hang En Cave trek very rarely runs if there is any chance of rain due to the nature of the trek and the location of the cave.
Bicycling and kayaking, trekking, camping and swimming at allowed points along the rivers.
With the souvenir shop at Phong Nha tourism center, the guest can get handicrafts, brocades, stones, bead products, bamboo and rattan products (rattan baskets, traditional conical hat ...), seafood (dried shrimp, dried squid, dried fish) Herbs, wide Honey. And local market is located front of the Center for guest have the time to walking visiting.
Thien Duong Cave: Along with the new road, several restaurants -- at the site entrance, as well as at the top of the 500 stairs! -- were being built for visitors in Spring 2011.
In Dong Hoi, there is a range of hotels/guesthouses, as well as at least one beach resort. About 1 hour travel time from Dong Hoi to the park.
At least two idyllic options very close to the park:
In Phong Nha Town near the cave boat dock there are several budget level guesthouses along the road TL20 (intersection with the giant sign that says Phong Nha Ka Be National Park) for around 150,000 dong or more.
Check park regulations first, or go with an organized tour. Park rangers are very suspicious of undocumented visitors overnighting in the park.
Be cautious driving on the road to/from Dong Hoi; avoid night driving.
Bring mosquito repellent.
By Motorbike: If the weather is good (and only then!) do consider the route to Khe Sanh. It is a 230km ride along the Ho Chi Minh Highway with the most stunning views and almost no traffic. Be aware that there is almost nothing in between. The first place to buy Gas is at Kilometer 82 and it comes with a very steep price (40000 Dong per liter). You will probably get to Khe Sanh on a full tank with a Honda Win but don't gamble. There are some smaller pubs and places to eat along the road but especially if the weather is warm make sure you have enough water with you. Also be aware that the weather can easily change, that you will take a lot of time, especially as you will feel the need to stop every few kilometers to shoot photos. So leave early and don't push it too hard. There are some places to stay in Khe Sanh.