Formed approximately 250 million years ago, give or take a few million years, Phong Nha Cave is the largest and most beautiful cave in Vietnam. Located in the village of Son Trach, 55km northwest of Dong Hoi, it was designated a Unesco World Heritage site in 2000. It’s remarkable for its thousands of meters of underground passageways and river caves filled with abundant stalactites and stalagmites. In November and December the river is prone to flooding and the underground cave may be closed.
In 1990, a British caving expedition explored 35km of the cave and made the first reliable map of Phong Nha’s underground (and underwater) passageways. They discovered that the main cavern is nearly 8km long, with 14 others caves nearby .Phong Nha means “Cave of Teeth”, but, unfortunately, the “teeth” (or stalagmites) that were by the entrance are no longer there. Once you get further into the cave, it’s mostly unspoiled. There’s also a dry cave in the mountainside just above Phong Nha Cave. You can walk to it from the entrance to Phong Nha Cave (10 minutes) – look for the sign to Tien Son at the foot of stairs.
You should be aware that Phong Nha is heavily visited by Vietnamese groups. The cave itself is fantastic, the experience less so. That is unless you like your World Heritage sites to incorporate litter, noise, people climbing on stalagmites and cigarette smoke in the underground caverns. Of course these things are prohibited, but enforcement appears to be lax to say the least. Presumably these distractions can be avoided if you arrive early in the morning. The toilets might be less putrid then, too. The Phong Nha Reception Department, an enormous complex in Son Trach village, buy your admission ticket here and organize a bout to take you to the cave. Boats seats about 10, so it’s cheaper to share. The cave system is electrically lit, but you may want to bring a torch (flashlight), as some of the paths are poorly illuminated.
