Phong Nha Boat and Biking tour For those looking for the true Phong Nha experiences, this tour is the option to choose. The Boat & Bike Tour offers the perfect combination between the exciting adventure feeling and a feeling of soothing relaxation. 

Phong Nha Cave
Phong Nha Cave, also known as Nuoc (Water) or Lower Phong Nha Cave, is located in Son Trach Com- mune, Bo Trach District. The cave lies in- S|de the area of limestone mountains covered with tropical jungles of the Phong Nha - Ke Bang National Park. In the late 19th century, French priest Cadiere explored the cave and praised it "the most beautiful cave in Indochina." He was also the first person who discovered inscriptions by Cham people on the cave's walls.
Phong Nha Cave's mouth is 20m wide and 10m high, with numerous stalactites. The inside is spacious. The river is limpid and tranquil as if it is a large mirror. Deep inside the cave, the light fades out and disappears. In quietness, the noise of oars stirring water and echoes from mountain cliffs mix together and produce mysterious sounds. The system of Phong Nha caves has many branches. Up to the present, only the longest branch has been explored. This is a section of the subterranean river named Nam Aki, of which the open-air Son River is a part. In front of the cave is a breath- taking scenery of mountains and rivers. In rainy season, water from the Son River rises up and floods the cave entrance. The main cave in this system consists of 14 "chambers" linked together by a 1,500m long "water corridor." From the 14th "chamber", there are narrow corridors leading to large "chambers" in which limestone continues to be weathered. Boats go upstream for 800m and reach Nuoc Can Cave where there are only sand- banks and rocks. Stalagmites and stalactites in strange shapes rouse visitors 7 imagination. According to scientific reports of explorers from the British Royal Geographic Association, Phong Nha Cave is estimated 7,700m in length. In addition, it has "seven best": the most beautiful subterranean river, the highest and widest entrance, the most beautiful sand and rock banks, the most beautiful subterranean lake, the widest and most beautiful dry grotto, the most magnificent and fanciful stalactites and stalagmites, and the longest stream grotto.

Son River
Son River flows within the territory of Quang Binh Province. The upstream part of this river runs inside limestone mountains west of the province. There have been many legends about the origin of the name Son. A legend says it was about the love story between a rich girl and a poor man. Being opposed by family relatives, the desperate couple came to river to commit suicide. Their love story touched the heart of local people and the river hence was named Son (faithful) to commemorate the eternal love of the couple.
The pure Son River flows through romantic landscapes and countryside villages living along the river, offering visitors relaxing experiences. Chay River Chay River, deriving from Chay Waterfall, is a tributary of Son River. The lOkm-long Chay River boasts rich biodiversity of high value with many unique aquatic species which include anguilla marmorata and clupanodon thrissa listed in the lUCN's Red List. The color of water changes into emerald green, green, yellow... at differ- ent sections of the river. Taking a boat trip along Chay River, visitors will have chance to contemplate scenery of imposing limestone mountains, corn fields, saraca declinata flowers and enjoy traditional culture and daily life of local people living in old villages of Ha Loi, Na, Phong Nha, Tram, Me, Chay Lap...