By Jimmy, Halong Bay cruise specialist · Updated
Ao Ech 2026: Cat Ba’s Forest Frog Pond and Lan Ha Bay’s Calm Kayak Waters
Ao Ech (Frog Pond) is best known as a 3.2-hectare pond hidden in the forest of Cat Ba National Park, about 80 m above sea level, where trees 5–10 m tall grow straight out of the water on the trekking trail to Viet Hai village. Cruise operators also use the name for a sheltered stretch of Lan Ha Bay off Cat Ba’s east coast, used for kayaking and swimming.
Two places, one name (checked October 2026): The forest pond is an official sight inside Cat Ba National Park (park entry applies; trekking with a guide is recommended). The Lan Ha Bay kayak area called Ao Ech by some cruises is not a separately listed site; it is covered by the Lan Ha Bay fee. Check which one your itinerary means. Kayaking in the Cat Ba / Lan Ha bays was suspended by local authorities in late 2025; when it is not allowed, cruises use rowed boats, swimming or deck viewing instead, so check the rule in force for your date.
Ao Ech Area at a Glance
| Forest pond |
3.2 ha, about 80 m above sea level, inside Cat Ba National Park |
| Character |
Shallow water with trees growing from it; clear water that rarely dries completely |
| Access |
Forest trail of roughly 4–6 km from the park gate, continuing to Viet Hai Village (about 10 km in total) |
| Bay kayak area |
Calm water between islets off eastern Cat Ba in Lan Ha Bay |
| Activities |
Trekking and birdwatching (pond); kayaking and swimming (bay) |
| Fee |
Cat Ba National Park entry 160,000 VND adult (Hai Phong table; adjusted April 2026, confirm); bay area covered by the Lan Ha fee |
| Park hours |
07:00–17:00 |
| Best time |
October–April for trekking; April–October for kayaking |
| Find it |
Google Maps |
Is Ao Ech worth it? For fit walkers, yes: the flooded forest is one of Cat Ba’s most unusual sights and leads on to Viet Hai. On a cruise, the bay area is a pleasant kayak and swim stop rather than a destination.
Kayaking in calm water in the Ao Ech area of Lan Ha Bay
What Makes Ao Ech Special
A flooded forest on a hill
Most ponds on Cat Ba are tiny; Ao Ech covers about 3.2 ha halfway up the mountain, with trees standing in the water like a mangrove in the hills.
Gateway to Viet Hai
The pond sits on the classic trek across the national park’s core zone to Viet Hai Village.
Calm water in the bay
Offshore, the sheltered water that cruises call Ao Ech is ideal for beginners in kayaks.
The Forest Pond in Detail
Vietnamese reports describe the pond as about 3.2 ha at roughly 80 m altitude, with trees 5–10 m tall rising from clear water (Bao Van Hoa, June 2026). In the dry season the water shrinks and becomes shallow and muddy in places, according to Bao Hai Phong, so walkers should expect wet ground. Distances quoted from the park gate range from about 4 to 6 km, and the full trail on to Viet Hai is about 10 km.
Swimming from a cruise ship in sheltered Lan Ha Bay waters
Things to Do
1. Trek to the pond
Allow a full day if continuing to Viet Hai; go with a park or licensed guide.
2. Watch for wildlife
Birds and small animals use the pond; keep quiet and stay on the trail.
3. Kayak in Lan Ha Bay
On cruises, 45–60 minutes of guided kayaking in sheltered water.
4. Swim from the ship
When the crew allows, usually May–October.
Night plankton glowing in Lan Ha Bay
5. Look for glowing plankton
On some dark summer nights bioluminescent plankton sparkle in Lan Ha Bay when the water is disturbed; sightings are natural and never guaranteed.
Fees, Hours and Safety
| Item |
Details (checked October 2026) |
| Park entry |
160,000 VND adult / 80,000 VND child (Hai Phong table from August 2024; the park adjusted prices in April 2026, confirm on site) |
| Park hours |
07:00–17:00 |
| Bay fee |
120,000 VND adult (Lan Ha Bay); included in cruises |
| Safety |
Trek with a guide; carry water; life jackets for kayaking |
| Rules |
Stay on trails; no plant picking or litter |
How to Get to Ao Ech
| Option |
Notes |
| Trek from Cat Ba National Park |
Start at the park headquarters area; continue to Viet Hai and return by boat |
| Lan Ha Bay cruise |
Kayak or swim stop in the bay area on some itineraries |
| Boat tour from Cat Ba |
Ask for a kayak stop in eastern Lan Ha |
Best Time to Visit
| Months |
Pond (trek) |
Bay (kayak) |
| October–April |
Cooler, best for hiking |
Cool; kayak only |
| May–September |
Hot, humid, muddy after rain |
Warm; swimming |
See Halong Bay vs Lan Ha Bay for planning.
Ao Ech vs Dark and Bright Cave
|
Ao Ech |
Dark and Bright Cave |
| Experience |
Forest pond or open calm water |
Tunnels into a lagoon |
| Effort |
Long trek (pond) or easy paddle (bay) |
Easy paddle |
| Tide dependence |
Low |
High |
Our view: On a cruise, Dark and Bright Cave is the bigger thrill. For a land adventure on Cat Ba, the trek past Ao Ech Area to Viet Hai is unforgettable.
How It Fits a Lan Ha Bay Trip
- Cruise into Lan Ha Bay and kayak in calm water
- Swim at Ba Trai Dao
- On a Cat Ba stay, trek past the pond to Viet Hai and return by boat
Ships on Lan Ha routes include La Casta Star, Indochine Grand, Peony Cruise and Aurora Cruise.
Local Expert Tips
These tips come from more than a decade of arranging Halong Bay trips for international travellers.
- Wear proper trekking shoes; the trail is rocky and muddy
- Use insect repellent
- Start early and carry at least two litres of water
- Confirm which Ao Ech your itinerary means
Plan Your Visit
Compare Lan Ha Bay cruises or ask us to add a Cat Ba trek on WhatsApp +84 886 261 368. Best Price Guarantee included.
Frequently Asked Questions about Ao Ech
1. What is Ao Ech?
Ao Ech (Frog Pond) is a 3.2-hectare forest pond in Cat Ba National Park; cruises also use the name for a calm kayak area in Lan Ha Bay.
2. Where is Ao Ech in Cat Ba National Park?
On the forest trail from the park headquarters towards Viet Hai, roughly 4–6 km from the gate.
3. Why are there trees in Ao Ech pond?
Trees 5–10 m tall grow directly out of the shallow water, which makes the pond look like a flooded forest.
4. Does Ao Ech dry up?
It shrinks and becomes shallow in the dry season but rarely dries completely.
5. How long is the trek to Ao Ech?
A few hours one way; the full trail to Viet Hai is about 10 km.
6. Do I need a guide for Ao Ech?
Yes, a park or licensed guide is strongly recommended in the core zone.
7. Is there a fee for Ao Ech?
National park entry applies for the pond; the bay area is covered by the Lan Ha fee.
8. Can you swim at Ao Ech?
Not in the forest pond; swimming is possible in the bay area when cruises allow.
9. Can you kayak at Ao Ech?
Yes, in the Lan Ha Bay area cruises call Ao Ech.
10. Is Ao Ech on the way to Viet Hai Village?
Yes; see our Viet Hai Village guide.
11. Which cruises stop at Ao Ech?
Some Lan Ha Bay cruises use it for kayaking; ask on our contact page.
12. When is the best time to visit Ao Ech?
October–April for trekking; April–October for kayaking. See our best time guide.
13. Ao Ech or Dark and Bright Cave: which is better?
On a cruise, Dark and Bright Cave; on a Cat Ba trek, Ao Ech.
14. Is Ao Ech safe for children?
The bay is fine with life jackets; the trek suits fit older children. More tips in our Halong Bay FAQs. Plan Ao Ech with us.
