Halong Bay is located in the Northeast of Vietnam, belonging to QuangNinh Province. It is in the coastal area stretching from 1060 56’ to 1070 37’ east longitude and 200 43’ to 210 09’ north latitude. To the west and northwest, Halong Bay stretches from Yen Hung District, and includes the large urban areas of Halong City and Cam Pha Town, as well as Van Don Island District.

“Ha Long” is literally translated as "Bay of Descending Dragons." Prior to the 19th century, this name was not recorded in any document or archive. When mentioning the present-day Quang Ninh Sea or Ha Long Bay, old historical books often referred to them by the names of An Bang, Luc Thuy or Van Don. Not until the late 19th century did the name of Halong Bay appear on a French Marine Map.

On 17th December, 1994, the World Heritage Committee officially recognized Ha Long Bay as a World Natural Heritage Area at its 18th session in Phu Ket, Thailand, because of its universal aesthetic value according to criteria (iii) of the Convention.

Halong Bay is also the place of three glorious victories for the Vietnamese people, on the rivers of Bach Dang, Cua Luc and Van Don. These produced the national heroes Ngo Quyen in 938, Le Hoan in 981 and Tran Hung Dao and Tran Khanh Du in 1288. It also featured prominently in the two wars against the French and American foreign aggressors. Halong Bay has a strategic position for the development of socio, economic and internal security of Vietnam.

Bio-diversity is an important natural resource and needs to be preserved and conserved to maintain the ecological balance of the whole region. Bio-diversity is the general term used to reflect diversify and abundance in nature and includes all living things.

The Halong Bay area has a long geological history, commencing nearly 500 million years ago, stretching through various ancient geological periods involving the processes of orogeny earth movements, marine regression, tectonic down-warping and marine transgression. Between the Ordovician and Silurian periods (500 to 410 million years ago) the area was a deep sea. Later, between the Carboniferous and Permian periods (340 to 250 million years ago) the sea had become shallow.