Situated in the North-East region of Vietnam, Ha Long Bay is a bay in the Gulf of Tonkin comprised of regions of Ha Long City, the township of Cam Pha, and a part of the island district of Van Don. Ha Long Bay borders Cat Ba Island in the southwest, the East Sea in the east, and the mainland, creating a 120 km coastline. The bay itself has an area of 43,400 ha, consists of 775 islands, and forms a triangle with the island of Dau Go (Driftwood Grotto) to the west, the lake of Ba Ham (Three Shelter Lake) to the south, and the island of Cong Tay to the east.