Soi Nhụ culture (16,000- 5000 BC)
Located in Hạ Long and Bái Tử Long are archaeological sites such as Mê Cung and Thiên Long. There are remains from mounds of mountain shellfish (Christophorus), spring shellfish (Melania), some fresh water mollusk and some rudimentary labor tools. The main way of life of Soi Nhụ’s inhabitants included catching fish and shellfish, collecting fruits and digging for bulbs and roots.
Their living environment was a coastal area unlike other Vietnamese cultures, for example, like those found in Hoà Bình and Bắc Sơn.
Cái Bèo culture (5000- 3000 BC)
Located in Hạ Long and Cát Bà island, its inhabitants developed to the level of sea exploitation.
Feudal period History shows that Hạ Long Bay was the setting for local naval battles against Vietnam’s coastal neighbors. On three occasions, in the labyrinth of channels in Bach Dang river near the islands, the Vietnamese army stopped the Chinese from landing. In 1288, General Tran Hung Dao stopped Mongol ships from sailing up the nearby Bach Dang River by placing steel-tipped wooden stakes at high tide, sinking the Mongol Kublai Khan’s fleet.
During the Vietnam War, many of the channels between the islands were heavily mined by the United States navy, some of which pose a threat to shipping to this day.