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Welcome to Phong Nha - Ke Bang National Park World Natural Heritage Site Did you know? The park is famous for its beautiful caves and karst mountains There are 145 caves in the park which have been explored and mapped Many more caves are still to be explored in this vast remote jungle area The park area is currently about 85,000 hectares (ha) There are plans to enlarge it to about 120,000 It is part of a greater area of karst mountains, which includes the Hin Nam No National Biodiversity Conservation Area (NBCA) in neighbouring Laos Rich biodiversity The park is also unique because of its primary limestone forest and its rich biodiversity: nearly 2,700 plant species and 1,200 animal species have already been identified here More discoveries can be expected Son Doong is known as the largest cave passage in the world Explored only in 2009 it is 7.6 km long, 150 m high and 200 m wide Khe Ry cave, with the length of 18.9 km, is the longest river cave in Asia The combined surface of the Phong Nha-Ke Bang National Park (PNKB NP) and the Hin Nam No NBCA amounts to 200,000 and it is the largest and oldest karst area in South-East Asia Which caves can you visit? Starting by boat at Phong Nha, you can visit some of the park’s most beautiful caves: the famous Phong Nha Cave with its underground river, the beautiful Tien Son or Fairy Cave and the mysterious Toi or Dark Cave (The map of the boat tour is on the last panel) Situated about 30 km along the road from Phong Nha, Paradise Cave, is yet another cave that is also open to the public VIET NAM LAOS Entrance to Phong Nha cave Photo: Harald Schuetz The geological processes that form the area started millions of years ago Today, the mountains and caves display an impressive amount of evidence of Earth’s history It is a site that can help you to better understand the geological and geomorphical processes that shape the earth This is why UNESCO declared the park a World Natural Heritage Site in 2003 Photo: Bach Chien Why is the park a World Natural Heritage Site? Red-shanked Douc Langur (Pygathrix nemaeus) Please join hands with us to protect this Heritage Site for future generations! The Karst Mountains of PNKB The mountains in Phong Nha are made out of limestone layers, which were formed 465 to 250 million years ago at the bottom of an ancient sea About 250 to 230 million years ago, these layers were pushed upwards by the movements of tectonic plates and became exposed to rainwater The earth’s crust is formed by ‘tectonic plates’, which float on the liquid inner part of the earth They move very slowly; so slow that we not realise it When they touch, some parts of the earth’s crust are moved upwards, while others are moved downwards What does ‘karst’ mean? Did you know? The word ‘karst’ is derived from the Karst region of Slovenia It is now applied worldwide to any area of limestone, which is characterised by underground drainage, caves and sinkholes as a result of limestone being dissolved by freshwater The cracks, rock formations and caves in the illustration below are typical elements of karst mountains In the park you can see parts of the earth that used to be under an ancient sea millions of years ago Why are the mountains precious? Vertical crack Dry cave Horizontal crack The karst mountains of Phong Nha - Ke Bang took millions of years to develop They provide a unique environment for animals and plants The caves inside the mountains are important habitats for cave dwelling species Many of the animals and plants found here are already listed as threatened in the IUCN Red List and the Viet Nam Red Data Book Photo: Harald Schuetz Stalactites Stalagmites Wet cave Columns Underground river Limestone is a very special rock: it is formed in seawater but it dissolves when exposed to air and rainwater This dissolution happens not only via mechanical forces but also through a chemical process (See next panel) Karst mountain in PNKB NP Photo: Harald Schuetz Limestone – a very special rock Example of Karst formation in PNKB NP The mountains and caves took millions of years to develop If we destroy them, they can never be restored Caves and Grottos Why are there rock formations? PNKB NP lies in an area with an average annual rainfall of 2,000 to 2,500 mm The massive rainfall and the huge limestone massif are ideal conditions for cave formation This is why there are so many caves and grottos in the park Every rock formation in a cave begins with a single drop of water laden with mineral calcite When the drop falls, it deposits the thinnest ring of calcite Each subsequent drop that forms and falls deposits another calcite ring These accumulated drops form the huge stalactites that we can see hanging down from the ceiling Where the drops splash onto the floor, more of the solution evaporates and deposits tiny bits of calcite on the floor (forming stalagmites) Over millions of years, these tiny amounts add up to huge rock formations How were the caves formed? When the limestone layers were pushed out of the sea, they became cracked Rainwater becomes slightly acidic after absorbing carbon dioxide from the air When it falls into the limestone’s cracks, it is pulled down by gravity While seeping through the limestone, by a chemical reaction with the calcium carbonate in the stone, the water becomes a bicarbonate solution Drops of solution Stalactite Stalagmite Column Photo: Harald Schuetz The Kingdom of Lesser False Vampire Bat (Megaderma spasma) Is there life in the caves? You might think that caves are dark, cold places harbouring no life In fact, a number of animals prefer darkness and actually need to live in caves These animals are called troglobites They are amazing animals: • Some animals not have eyes, because they are of no use in the cave’s darkness • Many animals have extremely long antennae, because they need to feel their way around • Many bats and some birds use echolocation to find their way around in the dark Did you know? Photo: Howard Limbert This solution constantly carries away little particles of limestone The cracks grow increasingly wider, until they form huge caves inside the mountains An eyeless scorpion with a transparent body was discovered inside the Tien Son cave in 2010 and named the Viet Scorpion (Vietbocap canhi) Stalagmite in the Phong Nha cave Cave-dwelling animals cannot survive outside the caves The Treasures of Phong Nha - Ke Bang * * Famous Phong Nha Cave This cave is not only famous for its size and underground river, but also because it served as a hiding place with an underground hospital for the Vietnamese army during the American war The Ho Chi Minh trail runs through Phong Nha, which is why the area was subjected to heavy bombing during the war Inside the cave you can see writings of the old Kingdom of Champa (see photo) The Tien Son Cave lies 200 m above the Phong Nha cave Millions of years ago, the Son River probably flowed through Tien Son Over time, the water cut down through the rocks and the river now flows through the Phong Nha Cave The Tien Son Cave is now a dry cave, filled with huge columns, stalactites and stalagmites * Ecological and Cultural Tourism Centre, Phong Nha Village Phong Nha-Ke Bang National Park Beautiful Tien Son Cave Mysterious Dark Cave The mysterious Dark Cave (Hang Toi) is situated approximately km west from the Phong Nha cave on the bank of the Chay River The cave’s entrance is surrounded by a dark forest, a favourite place for monkeys If you are lucky, you might see one of them! * * Phong Nha Cave • Do not eat or leave any food in the caves • Do not leave the marked pathways • Do not touch the rocks Photo: Suzanne E Clark * Dark Cave • Do not smoke, litter or spit in the caves • Do not leave money or other offerings in the caves Park Headquarter Tien Son Cave Six rules of cave behaviour Champa Dynasty script remained in Bi Ki Chamber The animals living in the caves will go extinct if YOU not protect them! • Sssh! – Avoid loud conversations © giz, 2011
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