Cat Ba Island offers a bay of around 400 islands and 139 small beaches, a national park of more than 17,360 hectares with three peaks worth climbing, and a farming valley that no road reaches — enough for two full days at the very least. Our family runs a homestay in that valley, Viet Hai, and every week guests ask what is actually worth the time. This is our answer: fifteen things grouped by where they happen, each with the time it needs, the fixed fee if there is one, the months it works, who it suits and the one thing we would warn you about. If you only have room for three, take the full day on Lan Ha Bay by boat and kayak, a night in Viet Hai with dinner at one table, and Navy Peak the next morning.
| The bay | Lan Ha Bay: over 7,000 ha, around 400 islands, 139 small beaches; kayaking, swimming, floating fish farms, overnight cruises |
| The park | Cat Ba National Park, founded 1986, more than 17,360 ha; Ngu Lam peak 220 m, Navy Peak 259 m, the 9–12 km trek across to Viet Hai |
| The village | Viet Hai: 87 households, about 295 people, no road link; cycling, the fish stream, Tien Duc cave, dinner at one long table |
| After dark | Bioluminescent plankton on the darkest nights from May to September; squid fishing from overnight boats, best June–September |
| Fixed fees | Lan Ha Bay ticket 120,000 VND adult / 60,000 VND child (free under 6 or under 1.2 m); park main gate 160,000 / 80,000 VND; Kim Giao–Ngu Lam–Trung Trang route 120,000 VND; Ninh Tiep–Tien Duc route 80,000 VND; electric cart 50,000 VND; bicycle 30,000 VND a day |
| Best months | October–November for everything; March–April next; May–September for swimming and plankton, with storm closures; December–February for walking |
| Our top three | Full day on the bay by boat and kayak · a night in Viet Hai · Navy Peak at dawn |
On this page: On the water · On foot · In the village · After dark · Rainy days and the town · Which activity for which traveller · FAQ
On the water: Lan Ha Bay
Lan Ha Bay is the eastern side of the island: over 7,000 hectares, about 400 limestone islands, 139 pockets of sand, and a fraction of Ha Long’s boat traffic. Boats leave from Ben Beo harbour or our village pier, and every crossing pays the same state ticket, 120,000 VND per adult and 60,000 VND per child, free under six or under 1.2 m. The sea runs 28–30°C from May to September, 25–27°C in October and November, 18–21°C from December to February.
1. Kayak through Bright and Dark cave into the lagoons
A low rock tunnel only a kayak fits through, opening into a closed lagoon ringed by cliffs — the best-known paddle in the bay. Time: an hour or two, usually within a boat day. Fee: the bay ticket only. Best months: October to April for calm water; fine in summer if you go early. Who it suits: almost everyone, including first-timers and children in a double kayak with an adult; the tunnel is short and the water flat. Caveat: by late morning it is the busiest spot on the bay; boats from the village side reach it before or after the crowd. Never paddled? Start with the Lan Ha Bay kayaking guide for beginners.
2. Spend a full day on the bay: swimming, a fish farm and lunch on board
The day boat is how the bay is meant to be seen: Bright and Dark cave, a swim from the boat or a cove, lunch cooked on board, an hour at a family fish farm where grouper and cobia grow in floating pens, a second paddle in the afternoon. Time: seven to eight hours. Fee: the bay ticket; the boat itself is priced by season and group size. Best months: May to November for swimming; October and November are the finest. Who it suits: everyone — no walking, so older travellers and small children do well. Caveat: a storm warning closes the bay to every boat, sometimes for a day, occasionally three. In summer keep a spare half-day, and run our two-minute boat safety check before boarding anything.
3. Swim and paddle at Ba Trai Dao
Three small coves under limestone cliffs towards the outer edge of the bay, with the clearest water we know on this side; kayak between them or, on some boats, stand on a paddleboard. Time: an hour or two as a stop on a boat day. Fee: the bay ticket. Best months: May to October, when the water is warm enough to stay in. Who it suits: swimmers, couples, anyone who wants a beach with nobody on it. Caveat: the sand is partly under water at high tide and can vanish altogether; there is some coral, but visibility varies with tide and season, so treat snorkelling as a bonus.
4. Sleep on the water: an overnight cruise, now across both bays
A night at anchor is a different bay: dinner on deck, the boats gone quiet, the karsts still there at first light. Since 20 April 2026 licensed cross-bay routes let one cruise board in Ha Long Bay and finish in Lan Ha; some itineraries stop at the mouth of our valley. Time: two days, one night. Fee: the bay ticket; the cruise is priced by cabin and season. Best months: October to April for clear air and calm anchorages. Who it suits: couples, first-time visitors to Vietnam, anyone who wants both bays in two days. Caveat: a cruise runs to its own timetable, and you kayak and swim where it anchors, not where you choose. Choosing a boat is covered in our Lan Ha Bay overnight cruise guide, the new routes in Cat Ba as the gateway to both bays in 2026. Our 3-day cruise and homestay combines the cruise, a cooking class on board, the night in Viet Hai and Navy Peak.
5. Land on Monkey Island (Cat Dua)
A beach with a resident troop of macaques and a short, steep trail to a viewpoint, on most day-boat routes from Ben Beo. Time: about an hour. Fee: the bay ticket. Best months: October to April, when the rock on the trail is dry. Who it suits: families with older children who can keep a bag closed, and anyone who wants a swim with a story. Caveat: the monkeys take anything edible from an open hand or bag, so keep food out of sight. They are macaques, not the Cat Ba langur, which lives on coastal cliffs and is seen from the water, if at all — see where to look for the Cat Ba langur.
Our full-day Lan Ha Bay boat tour leaves from the Viet Hai side, which puts you in Bright and Dark cave before or after the town boats: kayaking, swimming, lunch on board and a family fish farm, bay ticket included. In plankton season we add sunset and night kayaking on the darkest nights of the lunar month. Rates move with the season and group size — ask us for the current one.
On foot: Cat Ba National Park
Founded in 1986, the park covers more than 17,360 hectares of forest and sea, with 1,595 plant species, over 1,900 land animals and roughly 1,045 hectares of primary forest. Entry is charged by route: 160,000 VND per adult and 80,000 VND per child at the main gate, 120,000 VND on the Kim Giao–Ngu Lam–Trung Trang route, 80,000 VND on the Ninh Tiep–Tien Duc route on our side. Three walks are worth your time.
6. Climb Ngu Lam peak through the Kim Giao forest
The classic short walk from park headquarters: up through Kim Giao trees to a 220 m summit looking across ridge after ridge of karst. The same ticket covers Trung Trang cave, a passage of about 300 m through the hill nearby. Time: about 1 hour 45 minutes return; add half an hour for the cave. Fee: 120,000 VND adult / 60,000 VND child. Best months: October to April; in summer go before nine. Who it suits: most walkers, including children who can manage steps. Caveat: the steps and bare rock near the top are slippery after rain, and the final stretch is more scramble than path. The other trails are compared in our Cat Ba National Park hiking guide.
7. Trek across the park to Viet Hai
The most memorable way to reach our village: from park headquarters over the ridge, past Ao Ech — a 3.2 ha freshwater swamp forest, the only one in this limestone — and down into the valley. Time: 9 to 12 km depending on the route, four to five hours. Fee: park entry, plus 350,000 VND to send your luggage ahead by boat, which you should. Best months: October to April; summer humidity turns it into hard work. Who it suits: fit walkers with a day in hand and proper shoes. Caveat: you will meet macaques, not langurs — the langurs passed 90 animals in late 2024 but live on coastal cliffs, nowhere near the trail — and the path is steep, rooty and poorly marked in places, so take a guide. Trung Trang cave is not on this route, whatever older posts say. The route is in the trek across Cat Ba National Park to Viet Hai.
8. Climb Navy Peak above Viet Hai
Navy Peak — Hai Quan, 259 m — rises directly above our valley and is a different hill from Ngu Lam. In 1965 the navy built a radar station on the summit, villagers helping; after repeated American bombing the equipment was moved in 1968 to a site by Tung Gau bay, and you climb to where it stood. The view runs 360° over the valley, Lan Ha Bay and the southern islands of Ha Long. Time: about three hours return from our gate. Fee: none fixed; we guide it from the homestay. Best months: October to April, always early. Who it suits: reasonably fit adults and teenagers who want the best view on the island. Caveat: the upper section is bare, sharp limestone with no shade — not for young children, not for a summer midday. A litre of water each.
| Walk | Height / distance | Time | Fixed fee | Difficulty |
|---|---|---|---|---|
| Ngu Lam peak | 220 m; from park headquarters | About 1 h 45 min return | 120,000 VND adult / 60,000 VND child (includes Trung Trang cave) | Moderate; steps, scramble at the top |
| Navy Peak | 259 m; from Viet Hai village | About 3 h return | None (guided from the homestay) | Moderate to hard; bare limestone, no shade |
| Trek across the park | 9–12 km; headquarters to Viet Hai | 4–5 h one way | Park entry 160,000 / 80,000 VND; luggage boat 350,000 VND | Hard; steep, humid, guide advised |
| Tien Duc cave walk | Forest trail from the village | 45–60 min | 80,000 VND adult / 40,000 VND child | Easy to moderate |
In the village: Viet Hai
Viet Hai is a farming valley of 87 households and about 295 people on the far side of the island, inside the national park, with no road linking it to the rest of Cat Ba — not by regulation, but by geography; what vehicles exist stay in the valley. The forest was cleared for rice around 1930, the name dates from 1959, mains electricity arrived on 16 August 2009, and in June 2025 it became Hai Phong’s 13th recognised community tourism site. Speedboat from Ben Beo takes about 15 minutes, then an electric cart of about 10 minutes along the 3.4 km lane, 50,000 VND per person. Day boats give the valley about forty minutes; these four things are why we say stay the night.
9. Cycle the valley road
The village road is about 1.6 km end to end, flat and concrete, with lanes off it to the rice fields, the fish stream and the trailheads; the lane to the pier adds 3.4 km each way through a tunnel in the hill. Time: an hour covers it; a morning lets you stop. Fee: bicycles are 30,000 VND a day, free for guests who book a tour with us. Best months: any; misty at dawn in March and April, golden in October and November. Who it suits: everyone from about six upwards — the one thing here for small children. Caveat: the appeal is the ordinariness — rice, chickens, a school, people at work; expect a showpiece and you will be through in twenty minutes. Loops are mapped in cycling in Viet Hai village.
10. Put your feet in the fish stream
A stream at the north-eastern end of the village where small fish nibble the dead skin from your feet — the wild version of a city fish spa. Time: half an hour, a short cycle from the centre. Fee: none. Best months: July to September, when the village’s own records note many more fish. Who it suits: children, and adults who have just walked in over the ridge. Caveat: from December to February the water is cold and the fish are few, so do not build a winter afternoon around it.
11. Walk to Tien Duc cave
The Ninh Tiep stream–Tien Duc cave route is the park’s trail on the village side, and it carries two histories. Tien Duc led part of the 1885–1889 uprising against the French and retreated into this valley after a large battle in 1889; the cave has carried his name since. Long before that, people lived in it: Tien Duc and the nearby Ang Giua cave hold bones and thick shell layers left roughly 6,500 years ago. Time: 45 to 60 minutes through forest. Fee: 80,000 VND adult / 40,000 VND child. Best months: all year; carry water in summer. Who it suits: families and anyone who wants the park without the ridge. Caveat: the cave is a place with a story rather than a spectacle, so bring the story and a torch. Keen walkers can continue past Ao Ech to park headquarters in about 2.5 hours more.
12. Eat dinner at one long table
The part day visitors never see. At our homestay dinner is served at a single long table and everyone staying that night eats together: free-range chicken with ginger, fish soup, crisp-fried dried fish, garden greens, valley rice, banana or honey wine if you want it. Northern farmhouse cooking plus what the bay sends over — not a “traditional Viet Hai dish”, because no such thing is recorded. Time: the evening. Fee: per meal; breakfast is included in the room. Best months: any; from December to February you eat in a jumper. Who it suits: solo travellers most of all, who leave with a table of new acquaintances. Caveat: seafood hotpot or barbecue needs a day’s notice, and the quick-food menu takes about 20 minutes, so say what you want when you book the boat. A typical evening is in what to eat in Viet Hai village.
Our signature trip is 2 Days in Viet Hai: pick-up in Hanoi, the full day on Lan Ha Bay that lands you at our pier in the afternoon, dinner at the long table and the morning in the valley before the return, every ticket and transfer included. Add a second night and we take you up the Navy Peak hike at first light. Rates move with the season and group size — ask us for the current one.
After dark
Two of the best things on Cat Ba happen after the day boats have gone in, and both depend on the moon.
13. Kayak through bioluminescent plankton
On the darkest nights of the lunar month, from May to September and sometimes into early October, the water on the village side lights up blue-green wherever a paddle or a hand moves through it. We leave the pier at sunset, wait for full dark, and paddle back through it. Time: two to three hours. Fee: none fixed. Best months: May to September, in the days around the new moon only. Who it suits: couples, patient photographers. Caveat: it is never guaranteed — moonlight, cloud after rain, wind or a cold snap can all dim it — so we plan by the lunar calendar and say honestly when the odds are poor. How it works is in the bioluminescent kayaking guide.
14. Fish for squid from the deck
After dinner, overnight boats and some evening boats hang a lamp over the stern and hand out lines; the squid come up to the light and you jig for them. Time: an hour, or as long as you like. Fee: included on most cruises. Best months: June to September. Who it suits: families with children who can stay up, and anyone happy on deck in the dark. Caveat: a pastime rather than a harvest — some nights nothing bites — so go for the deck and the dark and count squid as a bonus.
Rainy days and the town
Hai Phong records around 116 rainy days a year, most between May and September, and a storm warning takes every boat off the water; Cat Ba town is where you wait it out. The Cat Co beaches — 1, 2 and 3, linked by a cliff path — are swimmable and close to the hotels, but in 2026 they sit beside a large seafront reclamation and construction project, explained in Cat Ba construction 2026: where to stay. Cannon Fort, on the 177 m hill 2–3 km above town, has the classic sunset view over the harbour, but access has been unreliable recently, so ask locally before climbing. A fuller wet-weather plan is in what to do on Cat Ba when it rains.
15. Go underground at Hospital Cave
Between 1963 and 1965 soldiers and islanders built a three-storey concrete hospital inside a mountain about 13 km from town, and it treated the wounded through roughly a decade of the American war: about 2,000 m², more than a dozen rooms — wards, an operating theatre, a water tank, a kitchen, a cinema — and space for over a hundred patients. Time: twenty to thirty minutes inside with a local guide, plus the road there. Fee: ticketed at the door; not one of the city’s fixed fees, so ask locally for the current figure. Best months: any; it is the obvious rainy-day choice and cool in summer. Who it suits: anyone interested in the war, older children, everyone on a day the bay is closed. Caveat: without a guide it is empty concrete rooms; with one it comes alive, so pay for the explanation. It pairs with Ngu Lam and Trung Trang cave on a road day.
Cai Beo: a 7,000-year-old settlement under the fish farms
About 1.5 km south-east of town and the first thing every boat from Ben Beo passes, Cai Beo is a working settlement of fish-farm rafts above one of Vietnam’s most important prehistoric sites. Madeleine Colani identified it in 1938; excavations between 1973 and 2006 found three cultural layers going back some 7,000 years, and it became a national relic in 2009. The rafts have been consolidated in recent years, so the view is emptier than in older photographs. No separate trip is needed: look for it from the boat on the way out.
Which activity for which traveller
The ranking is ours, in the order we would give the fifteen if you could only take some; numbers in brackets refer to the list above. “Short trip” means one full day on the island plus a night.
| Our rank | Activity | Families | Couples | Solo | Trekkers | Short trip |
|---|---|---|---|---|---|---|
| 1 | Full day on the bay by boat and kayak (2, 1, 3) | Best | Best | Best | Yes | Best |
| 2 | A night in Viet Hai with dinner at one table (12, 9) | Best | Best | Best | Best | Yes |
| 3 | Navy Peak at dawn (8) | Older children only | Yes | Yes | Best | If you stay two nights |
| 4 | Bioluminescent night kayaking (13) | Children over ten | Best | Yes | Yes | Only near the new moon |
| 5 | Trek across the park to Viet Hai (7) | Skip | If both are fit | Yes, with a guide | Best | Skip |
| 6 | Overnight cruise, or the cross-bay route (4) | Yes | Best | Yes | Skip | Skip |
| 7 | Ngu Lam peak and Trung Trang cave (6) | Yes, from about eight | Yes | Yes | Yes, as a warm-up | Skip |
| 8 | Cycling the valley and the fish stream (9, 10) | Best | Yes | Yes | Rest day | Yes |
| 9 | Tien Duc cave walk (11) | Yes | Yes | Yes | Rest day | Yes, if staying |
| 10 | Monkey Island (5) | Older children only | Yes | Yes | Skip | Yes, on the boat route |
| 11 | Squid fishing from the deck (14) | Yes, on a cruise | Yes | Yes | Skip | Skip |
| 12 | Hospital Cave and Cai Beo (15) | Yes | Rainy day | Rainy day | Rainy day | Rainy day |
A note on money. Bay tickets, park routes, the cart and bicycles are fixed by the city and paid in cash; boats, cruises, rooms and transfers move with the season. There is no ATM in Viet Hai and many small places cannot take international cards, so withdraw in Cat Ba town before you cross. At the homestay we take VND, US dollars, euros and cards; from 1 January 2026 every bill carries 7% tax and cards a further 3% bank fee — details on our payment information page. If anyone quotes a “tour fee” several times the ticket price, walk on.
Frequently asked questions about things to do on Cat Ba
Answered by the Lan family in Viet Hai — the people who run the boats, cook the dinner and pick you up at the pier.
What is the best thing to do on Cat Ba Island?
A full day on Lan Ha Bay by boat and kayak, with Bright and Dark cave, a swim and lunch at a fish farm. It shows you why the bay is a World Heritage site and needs no fitness. If you can add one more thing, make it a night in Viet Hai village rather than a second boat day; the valley after the day boats leave is what people remember.
How many days do you need on Cat Ba to do most of this?
Two days and one night cover the bay, the village and either a walk or a cycle. Three days add Navy Peak or the trek across the park, or a night on a cruise. Five let you do the whole list without hurrying and keep a spare half-day for weather. A single day from Hanoi buys you the boat and nothing else.
Is Cat Ba good for kids?
Yes. The boat day involves no walking, children under six or under 1.2 m ride the bay free, the kayak into Bright and Dark cave is short and flat, and the Viet Hai valley is flat enough for bicycles from about age six. Keep small children out of the Navy Peak climb and the trek, and keep all food closed on Monkey Island; the macaques are quick.
Can you see the Cat Ba langur?
Rarely, and only from the water. The population passed 90 animals in late 2024, the highest in about a century, but they live on coastal limestone cliffs, not on the forest trails, so trekkers meet macaques instead. A boat skirting the right cliffs early in the morning gives you a chance; nobody honest will promise a sighting.
Is kayaking on Lan Ha Bay safe for beginners?
Yes, inside the islands. The sit-on-top doubles are stable, life jackets are worn, and the water in the lagoons and around Bright and Dark cave is flat. The outer islands and Ba Trai Dao need calm conditions and a guide. No boat sails under a storm warning, and a good operator cancels before you reach the dock; our boat safety guide lists what to check before boarding.
When is the best time of year for activities on Cat Ba?
October and November: warm water, clear air, thin crowds, and every activity on this list works. March and April come next, with misty mornings on the peaks. May to September is the season for swimming, the fish stream, squid and plankton, but also for typhoons and closed bays. December to February is cool and grey, empty, and best for walking rather than swimming.
How do I book a boat tour or a trek on Cat Ba?
Ben Beo harbour has no ticket office and no timetable; boats are arranged, not scheduled. Book a day ahead with your homestay or hotel, or directly with a family operator, and confirm what is included: the bay ticket, kayaks, lunch and the pick-up point. Treks across the park need a guide arranged the day before and your luggage sent round by boat. We arrange all of it for our guests by WhatsApp.
Is there an ATM in Viet Hai village, and do I need cash?
No ATM in the village; the nearest are in Cat Ba town. You need cash for the bay ticket, the park route fees, the electric cart and bicycles, and for most small restaurants and boat operators, which cannot take international cards. At the homestay you can pay in VND, US dollars, euros or by card with a 3% bank fee; every bill carries 7% tax since 1 January 2026.
Planning your days on Cat Ba?
Tell us your dates, how many of you there are and how much walking you want. We will put the fifteen in the right order for your trip, say which nights the plankton is likely, and arrange whichever parts you want handled, with current rates. WhatsApp +84 363 934 325 or send a message here — we answer in English, usually within the hour.
Read next
- Cat Ba Island travel guide
- Cat Ba itineraries for 2, 3 and 5 days
- Lan Ha Bay: the complete travel guide
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Where to stay in Viet Hai
If this trip brings you into the village, the rooms and bungalows at Lan Homestay are a few minutes on foot from the centre: the garden bungalow (triple) works well for families, and the mountain-view double room for couples.
