Situated in the north-east region of Viet Nam, Halong Bay is a part of Bac Bo Gulf and comprises the sea area of Halong City, Cam Pha Town and a part of Van Don island district, Quang Ninh Province. It borders Cat Ba Island to the south-west, the mainland to the west with a 120km-long coastline.
Halong Bay covers a total area of 1,553km², including 1,969 islands of various sizes, 989 of which have been given names. There are two kinds, limestone and schist, which are concentrated in two main zones: the south-east (belonging to Bai Tu Long Bay) and the south-west (belonging to Halong Bay). The average geological age of the islands is between 250 and 280 million years old.
Halong Bay has been called by the great national poet Nguyen Trai: “a marvel of the earth erected towards the high skies”. While exploring the bay, tourists will feel lost in a legendary world of stone islands which shapes change depending on the angle and the light. There are many names given to islands according to their shapes and forms such as Hon Dau Nguoi (Human Head Islet), Hon Rong (Dragon Islet), Hon Canh Buom (Sail Islet), Hon Trong Mai (Cock and Hen Islet)…
The beauty of Halong Bay does not consist only in the forms of its mountains, islands and the colour of its waters, but also in its infinitely rich system of grottoes and caves such as: Thien Cung (Heavenly Palace Grotto), Dau Go (Driftwood Grotto), Sung Sot (Surprise Grotto), Tam Cung (Three Palace Grotto), Trinh Nu (Virgin Grotto)…. Each is a grandiose and refined natural architectural creation.
On December 17, 1994, Halong Bay was recognised as world natural heritage for its natural beauty at the 18th meeting of the World Heritage Committee of UNESCO in Thailand. On December 12, 2000, Halong Bay was recognised as world natural heritage for the second time based on its geological value at the 24th meeting of the World Heritage Committee of UNESCO in Cairns, Australia. The recognised site covers an area of 434km², comprises 775 islands and forms a triangle: with Dau Go Island (Driftwood Grotto) to the west; Ba Ham Lake (Three Shelter Lake) to the south and Cong Tay Island to the east.