Caves and Grottoes system in Phong Nha - Ke Bang

Phong Nha-Ke Bang National Park is one of the world's two largest limestone regions. In comparison with 41 other world heritage sites which have karsts, Phong Nha has dissimilar geomorphic, geologic and biotic conditions. The karsts of Phong Nha can be traced back to Palaeozoic era, 400 million years ago. This makes Phong Nha the oldest major karst in Asia. If the Hin Namno, bordering Phong Nha on the west (in Laotian territory) was to be combined with the national park in a continuous reserve, the combined reserve would be the largest surviving karst forest in South-east Asia with the total area of 317,754 ha.
Phong Nha-Ke Bang covers 300 different grottoes and caves. Phong Nha cave is assessed by the British Cave Research Association (BCRA) as the top cave in the world due to its 4 top records: the longest underground river, the highest and longest cave, broadest and most beautiful fine sand beaches inside the caves, the most spectacular stalagmites and stalactites.
In comparison with three other national parks listed in UNESCO's World Heritage Sites in Southeast Asia, namely Gununng Mulu National Park in Malaysia, Puerto Princesa Subterranean River National Park in Palawan of the Philippines and Lorentz National Park in West Irian of Indonesia and some other karst regions in Thailand, China, Papua New Guinea, karst in Phong Nha-Ke Bang is older, has more complicated geological structure; diverse and complex underground rivers.
History of exploration
Champa inscriptions carved on steles and altars in the cave demonstrate that people had inhabited the cave long before the area was annexed by Vietnam in the nam tien southward expansion.
In 1550, Dương Văn An was the first Vietnamese man to write about Phong Nha cave. Phong Nha cave was depicted in 9 urns in the Citadel of the Nguyen Dynasty in Huế.
In 1824, Phong Nha cave was conferred the title "Diệu ứng chi thần" by king Minh Mang. It was also conferred by Nguyen kings as "Thần Hiển Linh".
In the late 19th century, Léopold Michel Cadière, a French Catholic priest, conducted an expedition to explore Phong Nha cave, where he discovered Champa scripts. He proclaimed Phong Nha cave "The number one cave of Indochina". In July 1924, an English expeditionist, Barton, stated that Phong Nha cave is second to none of famous caves of Padirac (France), Cuevas del Drach (Spain) as far as the beauty and miracles are concerned.
In 1935, a local inhabitant accidentally discovered a beautiful cave 1 km from Phong Nha cave mouth, at an elevation of 200 m. It was called Tien Son cave (Fairy-tale cave), or Dry cave due to the fact that its inside landscape is similar to fairy-tales and it has no underground river.
In 1937, the Bureau of Tourism of French Resident Superior (in Huế) issued a brochure to introduce tourism in Quang Binh and Phong Nha Cave was included in this introduction. This tour site is ranked second in French Indochina. Before 1990, several explorations were conducted by Vietnamese and foreign groups but the mystery of this area still remained. From 1990 on, there marked a turning point in discovering activities, from exploration to research, thus full documents for submission to UNESCO for World Natural Heritage nomination were made available.
For the first time in 1990, Hanoi University accepted the cooperation proposal of the British Cave Research Association. They combined efforts in exploring and researching caves and grottoes in the area comprehensively. The first exploration was conducted in 1990 by a group from the British Cave Research Association and Faculty for Geology and Geography of Hanoi University, led by Howard Limbert. They completed research of a large part of Vom Cave.
In 1992, the second exploration was conducted by a group of 12 British scientists, six professors from Hanoi University. This time, this group completed their exploration of 7,729 m of Phong Nha Cave and 13,690 m of Vom Cave and adjacent caves and grottos.
In 1994, a third exploration was carried out by a group of 11 British scientists and five Vietnamese professors of Hanoi University.
Scientists discovered and studied 20 caves with a total length of about 70 km, of which 17 of these are in located in the Phong Nha area and three in the Ke Bang area. In 1999 scientists from the Vietnam-Russia Tropical Centre also conducted zoological and botanical surveys in the Ke Bang area. Phong Nha cave is 7729 m long, contains 14 grottos, with a 13,969 m-long underground river.
From the results of these three explorations, more thorough knowledge of the cave and grotto systems in this park was made available to the Vietnamese and local government for the protection, planning, and tourism development of this park.
In 2005, scientists from the British Cave Research Association discovered a new cave and named it Paradise Cave (động Thiên Đường). The newly discovered cave was acclaimed by the British scientists as "the largest and the most beautiful cave in Phong Nha-Ke Bang area".
On June 1, 2006, the Ministry of Culture and Information of Vietnam issued a stamp collection of depicting various landscapes found in Phong Nha-Ke Bang.
The Phong Nha cave
The scientists have surveyed 44.5 km of grottos in this cave so far, but tourists can only penetrate to a distance of 1500 m. Notable caves and grottos: Phong Nha Cave system:
- Dark Grotto (Hang Tối): located upstream of Son River running to the branch of Chay River on the left. This cave is 5,258 m long and with a height of 83 m. The entry is high and wide with heavy forest around the cave mouth.
- E Grotto (Hang E): a 736 m-long grotto accessible by Ho Chi Minh Trail.
- Cha An Grotto (Hang Chà An): a 667 m-long grotto, with the width of 15 m.
- Thung Grotto (Hang Thung): This grotto has an underground river of 3351 m, with the height in some part exceed 133. This river receives water resources from Rao Thuong.
- En Grotto (Hang Én): a 1645 m long, 78.6 m high grotto. The grotto is wide, there is fine sand field inside. This grotto is the habitat of thousands of sparrows.
- Khe Tien Grotto (Hang Khe Tiên): located south of Phong Nha, this grotto is 520 m long.
- Khe Ry Grotto (Hang Khe Ry): located south of Phong Nha. The grotto is where the stream Khe Ry (a 13.817 km or 8.585 mi long stream at the elevation of 120 m, originating from a mount 1300 m high) runs out.
- Khe Thi Grotto (Hang Khe Thi): The Khe Thi stream originating from the mount and runs underground at this grotto.
Vom Cave systems
- Vom Grotto (Hang Vòm): a 15.05 km long, 145 m high grotto with several underground rivers, pools. This grotto features several spectacular stalagmite and stalactites.
- Dai Cao Grotto (Hang Đai Cao): this grotto is a connection of Vom Grotto. This grotto is 1645 m long, 28 m high.
- Duot Grotto (Hang Duột): This is a connection of Dai Cao Grotto with the length of 3.927 km and height of 45 m. There are some fine sand fields inside.
Ca Grotto (Hang Cá): a 1,500 m long, 62 m high grotto.
- Ho Grotto (Hang Hổ): A connection of Ca Grotto with the length of 1,616 m and the height of 46 m.
- Over Grotto (Hang Over): a 3,244 m long, 103 m high grotto, with the width from 30–50 m.
- Pygmy Grotto (Hang Pygmy): This 845 m long grotto has several streams falling from mounts.
- Ruc Caroong Grotto (Hang Rục Caroòng): This the habitat of Arem ethnic group. They live in the caves, grottos and on hunting, harvesting natural products.
Tien Son Cave
Tien Son cave is another beautiful cave in Phong Nha-Ke Bang area. Tien Son cave was discovered by a local inhabitant by accident in 1935. It is located in Son Trach Commune, Bo Trach District. The entry mouth of Tien Son is 1 km from Phong Nha cave, at an altitude of 200 m. This cave is 980 m in length. A 10 m deep hole is situated 400 m from the entry mouth, then a 500 m long underground cave, dangerous for tourists and therefore is open to professional expeditions only. Like Phong Nha cave, this cave features spectacular stalactites and stalagmites shaped like several fairy-tales. Stalactite and stalagmite columns and walls here create strange sounds like that of gong and drum if they are knocked with the hand. According to British cave scientists, Tien Son cave was created tens of million years ago when a water current holed this limestone mount in Ke Bang. Following a series of landforms and movement of rocks, this mass was levered or lowered, blocking the current and creating what is now Tien Son cave while the underground river redirected its current to Phong Nha cave. Although Phong Nha and Tien Son caves are located next to each other, there are no linking grottos between them.
Thien Duong Cave
Thien Duong (Paradise) Cave is a newly found cave in this area. It is regarded by British cave scientists as the largest and longest cave in Phong Nha-Ke Bang, with the most beautiful and spectacular stalactites and stalagmites in the park. Nevertheless, tourists are only able to visit some hundred meters and a comprehensive survey has not been conducted yet due to the danger it may create in the farther side and therefore knowledge of this cave is limited and it remains a mystery to the scientists.