The closest train station is in Dong Hoi, 40 kilometres away. The city is a common stop for north-south trains. The SE1, SE2, SE3, SE4, SE5, SE6, SE7, SE8, SE20 all stop at the station. It takes 10 hours to Hanoi, 3 hours to Hue, 23 hours to Ho Chi Minh City.
If you have a tour or trek in Phong Nha completed by 18:00, it is usually possible to catch the evening overnight train to Hanoi.
The local bus to Dong Hoi departs the Phong Nha boat station parking lot and picks up passengers at bus stops along the main street, including a stop in front of Easy Tiger Hostel. The green and yellow bus departs at 05:30, 06:00, then every hour until 17:00, travelling to the Dong Hoi central bus station, ben xe Nam Ly; from the bus station it's two kilometres to the train station, six kilometres from the airport. Wave at the bus driver or else it won't stop. It costs 35,000 dong and takes 90 minutes. Pay the driver directly.
Taking another bus from Dong Hoi isn't the greatest as destinations from the city are limited, with routes served with local buses, mostly in the form of old minibuses. If train (which is far more straightforward) is not an option, it's better to have your Phong Nha hotel or an agency make arrangements to get on the large bus companies/Open Tour buses passing through Dong Hoi. Hanoi, Hue, Da Nang, Da Lat are some of the possibilities.
A local bus to Da Nang departs at 05:30 and makes the round throughout the area (including a stop at Phong Nha Farmstay) picking up passengers before departing. Best to have your hotel confirm the time and pick up. The bus can drop you off on the highway at Dong Hoi and Dong Ha. Price depends on what mood the money collector is in and the size of your bag. We were told it should be 90,000 dong to Dong Ha; we were charged 120,000 dong. The journey to Dong Ha takes 4 hours.
Hotels also offer tourist shuttle services. There's a Phong Nha to Hue bus transfer that will include a stop at the forgettable Ben Hai River Museum and the must-see Vinh Moc Tunnels. It departs at 06:30 and you'll be in Hue at 12:30. This is a good way to catch at least some important Vietnam War history if you don't have any time for the DMZ. Cost is 500,000 dong per person.
You can count on the fact that a lot of travellers in Phong Nha will be headed to the same destinations such as Dong Hoi train station or Hue. A group sharing a private taxi will be comfortable and economical. Chat up others. Busy joints like Easy Tiger Hostel and Phong Nha Farmstay are also good about coordinating shared transfers.
Boats to Phong Nha Cave and Tien Son leave from the Phong Nha-Ke Bang Tourism Centre at the end of the main street. A boat costs 360,000 dong, which can be shared with up to 14 people. See our Phong Nha Cave coverage for full details.
Aside from the local bus, if you want to take a private taxi to Dong Hoi, it will cost around 400,000 to 500,000 dong and take 45 minutes. Hotels usually offer transfers for 400,000. Easy Tiger charges 500,000 dong for one person, but given the sheer volume of travellers the hostel sees, chances are good that you can share to make it more economical: two passengers, 250,000 dong per person; three passengers, 170,000 dong; four or more, 125,000 dong per person.
There are several motorbike rental shops on the main street, including Thang's Phong Nha Riders beside Easy Tiger, and hotels/guesthouses rent them as well. Rentals cost around 150,000 dong a day.
While the Easy Rider-type motorcycle tours haven't taken off like in other popular Vietnam tourist cities, Thang's Phong Nha Riders has licensed drivers that can take you around, which is highly recommended if you want to explore the countryside, the stunning drive through the National Park, Botanical Garden or Bong Lai valley, which is dirt road. Drivers aren't guides per se (English is limited) but they know good routes and will stop whenever you want for photos. It's easy enough get your hotel to communicate the itinerary you want. A full-day out will cost around 400,000 to 600,000 dong.
A bicycle is a great way to explore the surrounding countryside. Midrange hotels usually offer city bicycles as a guest perk. A decent mountain bike is a good investment for the dirt roads and the national park.