After breakfast, leave hotel for Phong Nha Caves, 55 km north of Dong Hoi. The caves are one of the five sites in Vietnam listed by UNESCO as World Heritage Sites. They were formed about 250 million years ago and have thousands of metres of underground passageways full of stalactites and stalagmites.
Take a boat ride on the Son River to spectacular Phong Nha grottoes including Bi Ky Cave and Cung