Phong Nha – Ke Bang National Park
lies in Quang Binh Province - the central Vietnam. Covering an area of
about 200,000 hectares, Phong Nha – Ke Bang situated in Quang Ninh, Bo
Trach, Tuyen Hoa and Minh Hoa districts, is 50km northwest of Dong Hoi
City.
Phong Nha - Ke Bang can be compared to a huge geological museum thanks to its
complicated geological structure with different categories of stone
including sandstone, quartz, schist, siliceous limestone, granite,
granodiorite, diorite, applet, pegmatite, etc. Phong Nha-Ke Bang is the
oldest and largest tropical karst formed 400 million years during the
main geological periods of the Earth, bearing the original topographic
and geologic characteristics. Experiencing major tectonic phases, high
mountain ranges and the depressed sedimentary basins were formed. These
fluctuations have also contributed to the diversity of geology,
topography, geomorphology.
Phong Nha - Ke Bang karst mountains can provide a lot
of valuable information about the Earth's prolonged geological process
through various periods, from the Paleozoic (about 400 million year ago)
to the Carboniferous and Permian (340-240 million years ago). It is
also noteworthy to mention a geological characteristic – the system of
underground rivers and grottos in limestone mountains.
In the non-karst geomorphologic area, there are many
low mountains covered by a floristic carpet. The erosion has created a
number of abrasion-accumulation terraces along the valleys of the Son
and Chay rivers and at the margins of the central limestone massifs. The
transition terrain consists of a diversity of rock intercalated by
limestone mountains.
Besides the historical value of geology, topography,
geomorphology, Phong Nha - Ke Bang is also favoured with the mysterious
and majestic landscapes by nature. The Phong Nha–Ke Bang Natural Park
still hides various myths of nature. It also has spectacular karst caves
formed for hundreds of millions of years.
Locating in the area with a high average rainfall,
however, few rivers and streams can be seen because water is absorbed to
run inside limestone mountains. Therefore over tens of million years,
water has eroded rocks, creating numerous caves in the area. The Phong
Nha grotto system has evaluated as the most value in the world by the
British Cave Research Association (BCRA) which held several world cave
records, as it has the longest underground river, highest and widest
entrance, the most beautiful sand and rock banks, the most magnificent
and fanciful stalactites and stalagmites.
Phong Nha-Ke Bang area is noted for its cave and
grotto systems as it is composed of 300 caves and grottos, divided into
three main systems: Phong Nha Grottos, Vom Caves, and Ruc Mon Caves.
The Phong Nha grotto system is 40km long in total,
rising from south of Ke Bang Limestone Mountain. The main entrances are
Khe Ry and En Grottoes situated at a height of 300m above sea level. The
grottoes of this tree-branch system run in the direction of
northeast-southwest.
The system of Vom caves is over 30km long, rising
from Ruc Ca Roong Cave located at a height of 360m above sea level and
ending with Vom Cave. The system runs south and north. Ruc Ca Roong
River sometimes hides in mountains, sometimes appears in narrow and deep
valleys, and flows into the Chay River at the entrance of Vom Cave.
The system of Ruc Mon caves that lies in the district
of Minh Hoa is also a large cave. However, the information about this
system is not abundant because few surveys have been conducted in this
area so far.
Next to the Phong Nha Grotto is Tien Son Cave - also
known as Dry Grotto or Upper Phong Nha, a famous beautiful cave in Phong
Nha – Ke Bang area - where features spectacular stalactites and
stalagmites shaped like several fairy-tales. In addition, the Thien
Duong Cave remains untouched, with a very splendid beauty, longer and
larger than Phong Nha or Tien Son Grottos. Especially, Son Dong Cave is
one of the most newly-found caves in the national park that found by a
British expedition in April 2009. It is regarded as the largest cave in
the world. The biggest chamber of Son Dong is over five kilometers in
length, 200 meters high and 150 meters wide.
With its characteristics of topography, climate, soil
and hydrography, Phong Nha - Ke Bang boasts a rich, diversified and
unique flora. Investigations show that Phong Nha - Ke Bang has a large
tropical forest floor. It covers 96.2 percent of the natural area, of
which nearly 90 percent is covered by primeval forests. The diversity of
rare and precious species of animals and plants in Phong Nha - Ke Bang
is corollary of its natural conditions, and is a feature of the forest
ecosystem.
Statistics show that the flora of Phong Nha - Ke Bang
belongs to 152 families, 511 branches, and 876 species, including 38
listed in Vietnam’s Red Book, 25 in IUCN’s Red Book (International Union
for Conservation of Nature and Natural Resources) and 13 endemic
species.
A very important discovery in this national park is
three rare and precious species – Sao la, Mang lon and Mang Truong Son -
were founded in this area. Especially, Sao la and Mang lon are new
species discovered in the world. Of the 81 recorded reptile and
amphibian species, 18 are listed in Vietnam’s Red Book and 6 in the IUCN
Red List of Threatened Animals. In addition, there are 259 butterfly
species, 72 fish species including 4 endemic ones in Quang Binh only and
one first found in Vietnam; 302 bird species including 15 species
listed in Vietnam’s Red Book and 19 in IUCN Red Book. Particularly,
black-comb blue pheasants (ga loi lam mau den), white-tail blue
pheasants (ga loi lam duoi trang) and peacocks are the global-level
endangered species. Phong Nha - Ke Bang is considered a huge biological
museum in Vietnam.
With its vivid evidences of the Earth's formation,
geological, topographic and geomorphologic history, mysterious
landscapes and the bio-diversity of the national park as well as its
unique historical and cultural values, Phong Nha – Ke Bang has been
declared a world natural heritage by UNESCO at the 27th meeting in Paris in July 2003.
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