Ha Long Bay archipelago is made up of 1,969 islands, both settled 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).
This unique UNESCO World Heritage Site is a popular place for tourists and it is good to know that large parts of Ha Long Bay are officially protected from development. The islands vary greatly in size and shape as well as structure.
Visitors might want to allow a few days to explore this magical bay as its attractions are extremely numerous.