The nearest large city is Dong Hoi, served by domestic flights from Hanoi and Ho Chi Minh City, and by the main north-south railway. Trains from Hanoi take around six hours; from Hue, about two and a half hours. From Dong Hoi, the park entrance and Phong Nha village are about 45 km — a taxi or a pre-arranged minibus transfer from your guesthouse. The journey takes under an hour on a decent road through flat farmland.
There is no direct public transport between Dong Hoi and Phong Nha village, though shared minibuses run at irregular hours. Most travellers arrange transfers through their accommodation, which typically costs around 150,000–200,000 VND each way. Motorbike rental in Phong Nha village is cheap and the roads in the park are well-maintained — this is a popular option for independent travellers covering more than one site.
Hanoi to Dong Hoi is served by several budget airlines including VietJet, Bamboo Airways, and Vietnam Airlines. The flight takes about an hour.