Not only is Phong Nha Grotto the World’s Natural Heritage Site or Vietnam Wonder, but also a relic system of the Ho Chi Minh historical trail which collaborates with Xuan Son Ferry in order to create a route supporting for the battleground of the South Vietnam during the war against the American Empire. Today, this place has become the first section of the Ho Chi Minh historical trail. Therefore, coming to Phong Nha Grotto, tourists in Vietnam travel visit this legendary street.
From Bo Trach Town of Quang Binh Province, following the Street 15 to the west about 50 kilometres, you will reach Xuan Son Ferry on Son River. This is considered as the starting point of the system of Ho Chi Minh Trail. Phong Nha Grotto stays 4 kilometres far from the ferry. Previously, all people and goods shelter in this cave to avoid bombs and bullets. Today, the Tourism Centre Phong Nha is located at 1 kilometre far from Xuan Son Ferry (where now a modern bridge has been built). Visiting this grotto, sitting on the boat drifting along Son River, watching the green, pure river water and the imposing mountain chain Bao Dai Son surrounding, tourists feel like their souls are open with the nature.
At the first sight, the grotto does not have any special features of a wonder if we just take a look from outside. But when passing the grotto gate, you can a very high arch with many various shapes and fanciful colours. The river seems black and unusually quiet. This is the underground river with the length of 13,969 metres. Following this way, you will enter the wet cave. If you want to go to the dry cave, at the grotto gate, you need to turn right to reach Tien Son Grotto which is located at the height of 20 metres around; this is the place called “the mansion of stalactites”.
In the system of Phong Nha Grotto, the most famous is Bi Ky Grotto. Here you can find a plenty of sparkling stalactities, especially on the cliff inside the cave, people have discovered 97 words of the ethnic group Cham. Until now, more than 300 caves have been found here. Among those, Phong Nha and Tien Son are the most beautiful grottos of the world.