The legend of Hạ Long has it that, “Once upon a time, soon after the Việt people established their country, invaders came. The Jade Emperor sent Mother Dragon and her Child Dragons down to earth to help the Việt people fight against their enemy. Right at the time invaders’ boats were rushing to the shore, the dragons landed down on earth. The dragons immediately sent out from their mouths a lot of pearls, which then turned into thousands of stone islands emerging in the sea like great walls challenging the invaders’ boats. The fast boats couldn’t manage to stop and crashed into the islands and into each other and broke into pieces.

 
After the victory, Mother Dragon and Child Dragons didn’t return Heaven but stayed on earth at the place where the battle had occurred. The location Mother Dragon landed is nowadays Hạ Long Bay and where Child Dragons descended is now Bái Tử Long. The dragons’ tails waving the water created Long Vĩ (present Trà Cổ peninsula) and formed a fine sand beach over ten kilometers long”.

Hạ Long Bay is located in the northeastern part of Vietnam and constitutes part of the western bank of Bắc Bộ Gulf, including the sea area of Hạ Long City and Cẩm Phả Town and part of Vân Ðồn island district. It abuts Cát Bà Island in the southwest. Toward the west is the shore with a 120 km-long coastline. It is located within 106o58’-107o22’ east longitude and within 20o45’- 20o50’ north latitude. The site is 1553 sq. km with 1969 islands of various sizes, of which 989 have been named.

The islands in Hạ Long Bay are mainly limestone and schist islands most lying in the two main areas: the southeastern part of Bái Tử Long Bay and southwestern part of Hạ Long Bay. These islands represent the most ancient images of a geographical site having a tectonic age of from 250 million to 280 million years. They are the result of many times of rising and lowering processes of the continent to form a karst. The process of nearly full erosion and weathering of the karst created the unique Hạ Long Bay in the world. In a not very large area, thousands of islands with different forms look like glittering emeralds attached to the blue scarf of a virgin. The area where many stone islands concentrate has spectacular scenes and world-famous caves and is the center of Hạ Long Bay Natural Heritage, including Ha Long Bay and a part of Bái Tu Long Bay.

The area is recognized as the World Natural Heritage that is the area of 434 sq. km with 775 islands. It looks like a giant triangle with Ðầu Gỗ Island (in the west), Ba Hầm Lake (in the south) and Cống Tây Island (in the east) as its three angle points. The nearby area is the buffer area and areas classified as national beauty spots in 1962 by the Ministry of Culture and Information.

Viewed from above, Hạ Long Bay looks like an extremely vivid huge drawing. This is a wonderful and skilful masterpiece of the Creation and of nature that turns thousands of dumb soulless stone islands into fantastic sculptural and artistic works of various graceful shapes, both familiar and strange to human beings. Thousands of islands emerging uneven in the fanciful waves look strong and magnificent but also mild and vivid. Amidst these islands we feel as if we were astray in a petrified legendary world. There are many names given to islands according to their shapes and forms. This one looks like somebody heading toward the shore: Hòn Ðầu Người (Human Head Island); that one looks like a dragon hovering above the sea surface: Hòn Rông (Dragon Island); another looks like an old man sitting fishing: Hòn Lã Vọng; some look like big sails struggling amidst the wind to set off for the sea: Hòn Cánh Buồm (Sail Island); then two islands look like a pair of chicken lovingly playing with each other above the sea: Hòn Trống Mái (Male and Female Chicken Island); and amid the vast sea stands an island like a big incense burner like a ritual offering to Heaven: Hòn Lư Hương (Incense Burner Island). All are so real that people are taken aback by them. Those stone islands have experienced unpredictable changes over time and they take different shapes from different angles of view. Here, we come to realize that they are not dumb inanimate things but are vivid and soulful.
Inside the stone islands are various breath-taking caves, such as Thiên Cung, Ðầu Gỗ, Sửng Sốt, Trinh Nữ, Tam Cung and others. These are really magnificent palaces of the Creation on earth. Long ago, Hạ Long Bay has been called by the great national poet Nguyễn Trãi: “a wonder of the earth erected towards the high sky”. Many men of letters from all over the world have been taken aback at the grandiose scenery of Hạ Long. They seem to get puzzled and incompetent as their treasure of vocabulary is not rich enough to depict the splendor of this place.

 

Hạ Long Bay is also attached to glorious pages of Vietnamese history, with famous sites such as Vân Ðồn, a bustling trade port in the 12th century, charming Bài Thơ Mountain, and not very far away from here is the Bạch Đằng River which witnessed two famous naval battles of the Viêt’s ancestors against invaders. Also, Hạ Long is one of the cradles of human kind with the glorious Hạ Long culture in the late Neolithic age, discovered at such archeological sites as Ðộng Mang, Xích Thổ, Soi Nhụ and Thoi Giếng.

Hạ Long is also home to great biodiversity with typical eco-systems like mangrove forest, coral and tropical forest. It is also home to thousands of plants and animals of numerous species, for example shrimp, fish and squid. Some species are particularly rare and can be found no where else.

With such special values, at the 18th Session of UNESCO’s Council of World Heritage held on 17 December 1994 in Thailand, Hạ Long Bay was officially placed on the list of the World Natural Heritage. In 2000, UNESCO recognized it as the World Heritage for the second time for its geographical and geomorphologic values. This confirms the global premier value of Hạ Long Bay.

Wherever you come from, whosoever you are and however old you are, you will certainly experience the same emotion and feeling when admiring this wonder of stone and water. And great experiences will always remain even when you leave the place. The legend of Mother Dragon and Child Dragons sending out pearls to form thousands of stone islands to stop invaders still serve as the soul of this invaluable heritage of the world.
Have you ever come to Hạ Long, the unique wonder of the world of its kind, to admire and explore secretes implicit in the place?

 

 

The most remarkable geological events of Hạ Long Bay’s history in the last 1, 000 years include the advance of the sea, the raising of the bay area and the strong erosion that has formed coral and pure blue and heavily salted water. This process of erosion by seawater has deeply engraved the stone, contributing to its fantastic beauty. Present-day Hạ Long Bay is the result of this long process of geological evolution that has been influenced by so many factors. Some of the most remarkable are: the formation of the limestone layer more than 1, 000 m thick during the Carboniferous and Permian periods (240 to 340 million years ago); and the development of the Hạ Long depression during the Neogene period (10 to 26 million years ago). The erosion process forming the limestone plain was most active in the Quaternary Pleistocene epoch (11, 000 to 2 million years ago). It is because of all these factors that tourists now visiting Hạ Long Bay are not only treated to one of the true wonders of the world, but also to a precious geological museum that has been naturally preserved in the open air for the last 300 million years.
At the beginning of the Cambrian era (500 to 570 million years ago), the area, which now forms Hạ Long Bay, was basically mainland, submitted to a process of rain erosion. At the end of the period, it was flooded, commencing the existence of Hạ Long Bay. During the Odovic and Silurian periods (400 to 500 million years ago), the area of north-east Vietnam was basically a deep sea, submitted to the constant activity of tectonic plates. At the end of the Silurian period, it underwent a phase of inverse-motion that created mountains deep under the water. From the end of this period and throughout the whole Devonian period (340 to 420 million years ago), the area was subjected to powerful forces of erosion from the hot and dry climate. At this point, Hạ Long was part of a wide mainland that comprised most of today’s East Sea and Chinese continental shelf. Due to tectonic activity, the Hạ Long area and the entire north-east region were raised from the depths at the end of the Devonian period. In the later Carboniferous and Permian periods (240 to 340 million years ago), a shallow and warm sea reformed, which existed for approximately 100 million years. It created two kinds of limestone: the Cát Bà layer of the early Carboniferous period (450 m thick); and the Quang Hanh layer of the middle Carboniferous and the early Permian period (750 m thick). These two layers constitute the majority of the islands of the Bay.

Passing into the early periods of the Contemporary era (67 million years ago), Hạ Long Bay existed in the environment of a high mountainous mainland due to the influence of strong mountain-forming phases. The middle of the Paleocene period saw these motions remain continuous and stable, while strong processes of erosion began, and after millions of years, a form of semi-highland topography took shape. The continuation of this erosion has progressively cut the highlands into blocks with altitudes similar to today's mountains.

Into to the Quaternary era, the process of erosion began dissolving the limestone-rich region of Hạ Long. The islands of today’s Hạ Long Bay are basically remnants of these mountains flooded during the early Holocene period. Rainwater flowed into crevices in the limestone that had formed from tectonic activity. This steady erosion constantly widened the cracks, eventually creating today’s formations. The middle and late Pleistocene epoch (11, 000 to 70, 000 years ago) marks the period when the famous caves and grottoes of the area formed.

The Holocene period (from 7, 000 to 11, 000 years ago) is notable for the advance of the sea. This movement reached its peak 4, 000 to 7, 000 years ago and forming today’s Hạ Long Bay. After that, 3, 000 to 4, 000 years ago, with the sea in a steady process of recession, Hạ Long culture began to develop. At the beginning of the late Holocene epoch, the level of the water once again increased, forming a marshy floor of canals and streams, and creating the water marks that can be seen on the stone cliffs of today.

Hạ Long Bay has a very complicated structure with its meandering coastline and many river mouths. Rich and diversified sources of food for many species of plants and animals are also found here. In particular, the bay, partitioned by thousands of large and small islands, creates areas of water with an average and stable sea level. Meanwhile, the climate in Hạ Long Bay is also very stable, with an average temperature of between 19 and 25ºC, and an average heat radiation rate of 17 kcal/ sq. cm/ month. It sees an average rainfall of 2, 000 to 2, 200 mm/ year. These favourable conditions have seen the development of many varied ecosystems.

 

Results of scientific research show that Hạ Long Bay features ecosystems of a tropical ocean region, such as: salt water-flooded forests, coral reefs and tropical rain forests.
In the sea surrounding Hạ Long, coral grows in many places, but is densely concentrated on the eastern and southern sides, far from the mainland. According to research conducted by scientists from the Oceanographic Institute, Hạ Long Bay is home to 163 species of coral, from 44 lines of descent and 12 families. Coral reefs are distributed everywhere, generally at a depth of 4 to 6m. The coverage rate of coral reef is 30% on average, but there are areas where it attains 70 to 80%, such as at Cống Ðỏ and Bọ Hung. The coral forests of Hạ Long Bay are a wonderful sight, with many extraordinary shapes and diversified colours. When the tide flows, the coral moves with the water, pumping as rhythmically as a heartbeat. At the same time, the reefs are residence to a great number of species: fish (107 varieties), water plants, algae and transitory animals and plants.

The salt water-flooded forests also offer especially interesting scenery along the coastline of Hạ Long Bay. These forests are chiefly concentrated in the zones of Tuần Châu, Cửa Lục and Ba Chẽ. Many species of salt water-flooded plants, the most diversified collection in North Vietnam, are found here. Also living in these flooded forests are a great many species of animals: migrating birds (37 species), sea-bottom animals (81 species) and fish (90 species belonging to 55 families). In particular, bottom-feeders account for 61% of the total species in the whole tidal region, with many species being of great economic value: arcae, meretrixes and all kinds of crustaceans.
The tropical rain forest ecosystem also features a rich quantity of species: đinh, hương, sến, táu trees. This is the residence of various rare and precious creatures: deer, weasels, squirrels and in particular, white-tabby and red-haired monkeys.
At the same time, there is a system of small caves along the sea, which are the living and development places for many animals and plants: seaweed, water plants, algae, fish and shrimp. Deeper into the water, there are also many species of shrimp, fish (almost 1, 000 species), abalone and other sea-specialities; harvested every year to the tune of several thousand tons.