Hon Gai (now part of Ha Long City) is part of the capital city of Qu廕τg Ninh Province. The city mainly lies on Bai Tu Long Bay, which adjoins H廕?Long Bay. It is located at about 160 km northeast of Hanoi. Hong Gai has long been the main source of surface coal in Vietnam, and its strip mines, especially during the colonial period, were infamous for their hard conditions approaching near slave labour.

H廕?Long city is divided into two parts: East H廕?Long and West H廕?Long. The eastern part (Hon Gai), where most of the official buildings and industry are concentrated, is connected by bridge with the western part (Bai Chay), considered to be more of a tourism attraction. Hon Gai remains gritty and dominated by coal.