Halong Bay is located in the northeastern part of Vietnam and constitutes part of the western bank of Bac Bo Gulf, including the sea area of Halong City, Cam Pha Town and part of Van Don island district, Quang Ninh Province. UNESCO recognized it as the World Natural Heritage two times.
The islands in Halong Bay are mainly limestone and schist islands most lying in the two main areas: the southeastern part of Bai Tu Long Bay and southwestern part of Halong 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 area where many stone islands concentrate has spectacular scenes and world-famous caves and is the center of Halong Bay Natural Heritage, including Halong Bay and a part of Bai Tu Long Bay.
Viewed from above, Halong 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.
Halong Bay is also attached to glorious pages of Vietnamese history, with famous sites such as Van Don, a bustling trade port in the 12th century, charming Bai Tho Mountain, and not very far away from here is the Bach Dang River which witnessed two famous naval battles of the Viet's ancestors against invaders.
Halong 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, Halong 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.