The islands concentrated in two main zones: the southeast (belonging to Bai Tu Long Bay), and the southwest (belonging to Halong Bay) forms the core zone of Halong Bay, which was designated by UNESCO as World Heritage Site. This area incorporates 434 km² with 775 islands, delimited by 3 points: Dau Go Island on the west, Ba Ham Lake on the south and Cong Tay Island on the east.
Ha Long Bay’s ancient karst landscape is the result of complex geological processes taking over 500 million years, from the earth’s movements, sea regression, down-warping tectonics, and sea transgression, creating thousands of limestone islands emerging from the sea.
Halong Bay, a mighty and unique artwork by nature with thousands of islands rising from the emerald water, is the number-one tourist destination of northern Vietnam. Halong Bay is recognized by UNESCO as the World Natural Heritage Site in 1994 and 2000 for its aesthetic and geomorphological values. With breath taking beauty, Halong Bay officially became the 29th member The Club of the Most Beautiful Bays of the World in July 2003