Ha Long Bay (also "Halong Bay") is in northern Vietnam, 170 km (105 mi) east of Hanoi. The bay is famous for its scenic ocean karst topography and is often included on lists of natural wonders of the world, including the UNESCO World Heritage list.

The Ha Long Bay archipelago is made up of 1,969 islands, both inhabited and uninhabited. These can be accessed from various ports, though in the special case of

Cat Ba

you can also arrive either by car, motorbike or bus (via Haiphong) or combined bus/boat (from Hanoi via Halong City).

Ban Sen, a thickly forested, almost uninhabited island reachable by ferries to Quan Lan from Cai Rong.

Cat Ba, the home of the endangered Cat Ba langur, a national park, numerous caves and the most popular destination in Ha Long Bay for tourists. It can either be accessed by local bus and ferry from Hanoi's Lương Yên bus station (recommended), by tourist boat from Halong City (a five hour "hard sell" ordeal; this is what the hordes of Hanoi package tourists do), or by local bus or ferry from Haiphong (less scenic). 

Quan Lạn, a historically significant outlying island with the beginnings of some tourism infrastructure and some beautiful beaches. Reachable by ferry from Cai Rong or also (reportedly) from Halong City.

Van Don, a large island that is well inhabited, little visited by tourists and connected by road to the mainland near Cửa Ông.

"Ha Long" means "Bay of Descending Dragons" (Chinese: 下龙湾; Xiàlóngwān), though prior to the 19th century this name was not recorded in any document or archive. When mentioning the present-day Quang Ninh Sea or Ha Long Bay, old histories often referred to them by the names of An Bang, Luc Thuy or Van Don. Not until the late-19th century did the name of Ha Long Bay appear on a French maritime chart. The Hai Phong News, a French newspaper of the time, had an article, Dragon appears on Ha Long Bay, reporting the following story: In 1898 a sub-lieutenant named Lagredin, skipper of the Avalanse, reported seeing a huge sea snake in Ha Long Bay. This was also witnessed by many of the crew. Thus emerged the European image of the Asian dragon. Whether this appearance of a strange animal resembling a dragon resulted in the name of Ha Long Bay is unknown.