1:45 pm | August 2, 2024

The bay consists of a dense cluster of some 1,600 limestone monolithic islands each topped with thick jungle vegetation, rising spectacularly from the ocean. The bay has a 120-kilometre-long (75 mi) coastline and is approximately 1,553 km2 (600 sq mi) in size with about 2,000 islets. The area designated by UNESCO as the World Natural Heritage Site incorporates 434 km2 (168 sq mi) with 775 islets, of which the core zone is delimited by 69 points: Dau Go island on the west, Ba Ham lake on the south and Cong Tay island on the east. The protected area is from the Cái Dăm petrol store to Quang Hanh ward, Cẩm Phả city and the surrounding zone.

A community of around 1,600 people live on Hạ Long Bay in four fishing villages: Cua Van, Ba Hang, Cong Tau and Vong Vieng in Hung Thang ward, Hạ Long city. They live on floating houses and are sustained through fishing and marine aquaculture (cultivating marine biota), plying the shallow waters for 200 species of fish and 450 different kinds of mollusks. Many of the islands have acquired their names as a result of their unusual shapes. Such names include Voi Islet (elephant), Ga Choi Islet (fighting cock), Khi Islet (monkey), and Mai Nha Islet (roof). 989 of the islands have been given names. Birds and land animals including bantams, antelopes, monkeys, and lizards also live on some of the islands. Almost all these islands are as individual towers in a classic fenglin landscape with heights ranging from 50–100 metres (160–330 ft), and height/width ratios of up to about six.

The climate of the bay is tropical, wet, sea islands, with two seasons: hot and moist summer, dry and cold winter. The average temperature is from 15–25 °C (59–77 °F), and annual rainfall is between 2 and 2.2 metres (6.6 and 7.2 ft). Hạ Long Bay has the typical diurnal tide system (tide amplitude ranges from 3.5–4 metres or 11–13 feet). The salinity is from 31 to 34.5MT in the dry season and lower in the rainy season.

Of the 1,969 islands in Hạ Long, only approximately 40 are inhabited. These islands range from tens to thousands of hectares in size, mainly in the East and Southeast of Hạ Long Bay. In recent decades, thousands of villagers have been starting to settle down on the pristine islands and build new communities such as Sa Tô Island (Hạ Long City) and Thắng Lợi Island (Vân Đồn district).

At present, the Quảng Ninh provincial government has a policy to relocate the households living in the bay to resettle, in order to stabilize their life and to protect the landscape of the heritage zone. More than 300 households living in fishing villages in Hạ Long Bay have been relocated ashore in Khe Cá Resettlement Area, now known as Zone 8 (Hà Phong Ward, Hạ Long City) since May 2014. This project will continue to be implemented. The province will only retain a number of fishing villages for sightseeing tours.