Hạ Long Bay is located in northeastern Vietnam, from E106°56′ to E107°37′ and from N20°43′ to N21°09′.
The
bay stretches from Yên Hưng district, past Hạ Long city, Cẩm Phả town
to Vân Đồn district, bordered on the south and southeast by the Gulf of
Tomkin, on the north by China, and on the west and southwest by Cát Bà
island.
The bay has a 120 km long coastline and
is approximately 1,553 km² in size with about 2000 islets. The area
designated by UNESCO as the World Natural Heritage Site incorporates 434
km² with 775 islets, of which the core zone is delimited by 69 points:
Đầu Gỗ island on the west, Ba Hầm lake on the south and Cống Tây island
