Depart from Hue for 3 hours to Phong Nha Caves. On the way we stop to visit some of the most famous battle-field in Vietnam War, Ben Hai River, Hien Luong Bridge, lying in the Demilitarized Zone of the Vietnam war. Have a lunch at at local restaurant then getting on boat and cruise along the river to Phong Nha Cave. The deeper one penetrates, the more magical are the natural aspects of the caves. After on boat for 700m, a large dry passage is appear, then you can walk to discover the cave for 500m more. You will have a chance to explore the remain of Cham Altars and Inscriptions inside. Return to Hue in the late afternoon and we arrive in Hue at 7 pm. End tour.