The largest island in the Ha Long archipelago, with a national park, a climbing scene and the beaches Ha Long Bay does not have.
Cat Ba is the practical alternative to a Ha Long cruise: an island you can stay on for several nights, with the same limestone seascape on its doorstep and considerably more to do than sit on a boat. Lan Ha Bay, on its southern and eastern side, holds several hundred karst islands and is generally considered the prettier half of the archipelago — quieter water, more beaches, and floating fishing villages that still work.
About half the island is national park, home to the Cat Ba langur, one of the rarest primates in the world with a population in the low hundreds and found nowhere else. The park has marked trails, including a demanding traverse to Viet Hai, a village on the far coast reachable on foot, by bike or by boat. The island is also the centre of rock climbing in Vietnam, with bolted routes on the karst walls and deep-water soloing straight off a boat in Lan Ha.
Cat Ba town, on the south coast, is a working harbour with a strip of hotels facing a row of floating restaurants. It is not beautiful, and the high-rise development of recent years has not helped. Stay a night to use the town's transport and food, then get out onto the water or into the park — that is where the island earns its place on a northern itinerary.
Best months
April to June, or September to November
Go in
Late spring and autumn
Avoid
July and August — domestic peak season and typhoon risk
Weather
Spring and autumn give warm water, calm seas and manageable humidity. July and August are hot and are also when Vietnamese families holiday here, so the town fills and prices rise. Winter is cool and often grey, with water too cold for comfortable swimming.
What to pack
Swimwear and a dry bag for boat days, plus proper shoes for the park trails — the limestone is sharp and the paths are rough.
4 places worth your time — tap any of them for the full write-up, including tickets and when to go.
The southern arm of the archipelago, with several hundred karst islands, dozens of small beaches and far fewer boats than Ha Long proper. Day trips from Cat Ba town cover kayaking, a swim stop and a floating fishing village; overnight cruises also sail here.
Around half the island, protecting limestone forest, caves and the endemic Cat Ba langur, one of the world's rarest primates with a population in the low hundreds. Marked trails range from a short summit climb to a demanding traverse across the island to Viet Hai.
A small farming village on the far side of the island, historically reachable only on foot or by boat and still without a road to Cat Ba town. Homestays, bicycles and a valley of paddy fields ringed by karst make it the quietest place on the island.
A hilltop artillery position above Cat Ba town, built by the French and later used by Vietnamese forces, with restored gun emplacements, tunnels and a lookout over the harbour, the Cat Co beaches and the islands of Lan Ha beyond.
Which neighborhood suits which kind of trip, and roughly what a night costs in each.
Where the ferries, buses and tour boats all start. Hotels face the harbour, restaurants line the front, and everything is bookable on the spot. Built-up and noisy in summer.
Three small coves a short walk or ride from town, plus a scattering of resorts along the coast road. Quieter, with direct beach access and sunrise over the water.
Per person, per day, excluding long-distance flights and trains. Season and booking window move these numbers more than anything else.
~$50 (1,300,000₫)per person
~$105 (2,700,000₫)per person
~$220 (5,500,000₫)per person
Converted at 25,400₫ to US$1, checked 2026-08. Use as a guide, not a quote.
Small things that make the trip cheaper, smoother and safer.
You might also like
Around 1,600 limestone islands in the Gulf of Tonkin, seen properly only from a boat that stays out overnight.
A thousand-year-old capital that still runs on plastic stools, motorbike horns and the smell of charcoal — and the natural first stop for the north.
Ha Long Bay's limestone towers, but standing in rice fields instead of the sea — and only 90 minutes from Hanoi.
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