Ha Long Bay: the islands, the cruises, the alternatives

Ha Long Bay: 1,600 islands, and how not to see them badly

Short answer

Ha Long Bay is a cluster of about 1,600 limestone islands in Quang Ninh province, inscribed by UNESCO in 1994 and extended in 2000 and 2023. The core zone covers 334 km² and 775 islets. The karst towers took 20 million years to form, on limestone laid down over 500 million.

Last checked: September 21, 2026

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What the bay is

	Figure
Limestone islands	About 1,600
Islets counted	Roughly 1,969
Bay area	About 1,553 km²
UNESCO core zone	334 km², 775 islets
Inscribed	1994, extended 2000 and 2023
Karst age	Limestone over 500 million years, towers over 20 million

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Tower karst, not scenery

The islands are fenglin, tower karst, and that word does more work than any adjective. Limestone laid down over 500 million years was lifted, cracked and then dissolved by rain for another 20 million until what was left standing were the towers, each one a remnant rather than a pile.

That is why they have vertical sides and flat water between them, and why they look the same at any scale: a hundred metres away or ten kilometres out.

Choosing the water

The core zone is 334 km² of the 1,553 km² bay, and it holds 775 islets. It also holds most of the boats. Two straightforward ways to get more water and fewer engines:

Lan Ha and Cat Ba, southwest and administered by Haiphong, with the same towers and a fraction of the traffic.
Bai Tu Long, northeast, which is the bay that appears in photographs when nobody else is in them.

Both are bookable the same way, and neither requires giving up the geology.

The night on the water

The argument for an overnight is not luxury. It is that the day boats leave, the engines stop, and for a few hours the bay is quiet in a way no day trip can show you. Morning on deck before the fleet arrives is the thing people remember.

The timber upper deck of a cruise boat with karst islands rising from flat water on every side — What the overnight buys is the hour after the day boats leave.

The argument against is the same as everywhere: a boat is a room you cannot leave. Read what the itinerary actually includes and how many cabins are aboard.

Getting there

Most people come by road from Hanoi on the expressway, which the bus platforms cover densely. Van Don airport in Quang Ninh is also on the government’s list of gates that accept an e-visa, which makes flying into the province possible if the schedule suits.

Transport options in general are in sleeper buses in Vietnam, the arrival into Hanoi is in Hanoi airport to the Old Quarter, and the visa rules are in the Vietnam e-visa.

Timing and signal

The northern pattern applies: cool and dry December to February, wet May to October, with 6 to 8 typhoons or tropical cyclones nationally in a year and sailings occasionally cancelled because of them. The month by month view is in when to go to Vietnam.

Coverage on the water is better than people expect near the shore and worse further out, which matters if a sailing changes. Sizing is in how much mobile data for Vietnam and the plans are in the Vietnam eSIM store.

Questions

How many islands are there really?

About 1,600 limestone monoliths, with roughly 1,969 islets counted across the wider bay. The UNESCO core zone is smaller and more specific: 334 km² containing 775 islets. Those are the waters the photographs come from, and also the ones everyone else is on.

Day trip or overnight?

An overnight puts you on the water at dawn and after the day boats leave, which is the whole difference. A day trip is four hours of driving for a few hours of bay. If the schedule allows exactly one night outside a city on your trip, this is a strong candidate for it.

What about Cat Ba and Lan Ha?

Cat Ba Island sits to the southwest and is administered by Haiphong rather than Quang Ninh, and the water around it carries a fraction of the traffic. Bai Tu Long extends to the northeast for the same reason. Same geology, same towers, fewer boats in the frame.

When is the weather right?

The north is cool and dry from December to February and wet from May to October, and the bay sits in that pattern. Winter is clear and cold with haze some days. Summer is green and warm with rain and the occasional cancelled sailing, since Vietnam sees 6 to 8 typhoons a year.

Can I get there without going through Hanoi?

Van Don airport in Quang Ninh is on the government's list of international gates that accept an e-visa, so it is possible to fly straight into the province. Most visitors still come by road from Hanoi, which is the cheaper and more frequent option.