YOU GONNA BE AMONG OF NOWHERE!
So just follow the track!
Air: The closest service is via Vietnam Airlines to Dong Hoi with flights to Hanoi and Ho Chi Minh City (Vietnam Airlines, VietJet Air, and Jetstar Pacific Airlines).
Train: 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.
Bus: A local bus goes from Dong Hoi to Phong Nha for 35,000 dong. It departs at 14:00 from Nam Ly bus station. The bus back to Dong Hoi leaves Phong Nha at 8:00, so you have to either stay overnight or try to go back with one of the tour buses.
Motorbikes: Motorbikes can be rented for 150,000 dong 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 Dong Hoi.
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.
All of those transportation options will lead you to Phong Nha town. From there, you can rent a motorbike for 150 000 atThang Travel servicethat is also a trusty mechanic store, the price includes tax and insurance. It takes around 5-10 minutes to come to Phong Nha Rustic Home southerly.
See more clearly through the map link below