Ao Ech Area: Lan Ha Bay Lagoon & Cat Ba Frog Lake
Ao Ech Area (Ao Ếch, “Frog Lake”) is a name used around Cat Ba Island in Hai Phong for two quiet natural spots: a sheltered, cliff-ringed stretch of water in Lan Ha Bay visited by small boats, and the Frog Lake in the forest of Cat Ba National Park on the classic trek to Viet Hai Village. Both lie within the UNESCO Ha Long Bay – Cat Ba Archipelago.
Status (checked October 2026): boat visits in Lan Ha Bay depend on current rules: kayaking in the Cat Ba bays was suspended in November 2024 pending new regulations, so ask your operator what is allowed. The national park trek past Frog Lake runs as normal with a guide; trails get muddy and slippery after rain.
Why Ao Ech Area is worth seeing:
- Calm, mirror-like water enclosed by green karst cliffs in Lan Ha Bay.
- Forest trek through Cat Ba National Park to Frog Lake and on to Viet Hai Village.
- Quiet nature away from busy beaches and cave sites.
- Easy to combine with Dark and Bright Cave and Ba Trai Dao.
Ao Ech Area at a Glance
| Vietnamese name | Ao Ếch (“Frog Lake”) |
|---|---|
| Location | Lan Ha Bay east of Cat Ba Island, and the forest of Cat Ba National Park; Cat Hai Special Zone, Hai Phong city |
| Known for | Sheltered lagoon water, karst cliffs, forest lake on the Viet Hai trek |
| Recognition | Within Cat Ba National Park and the UNESCO Ha Long Bay – Cat Ba Archipelago (2023) |
| How to visit | Lan Ha boats from Ben Beo Pier or cruises; guided trek from the national park headquarters at Trung Trang |
| Fees | Lan Ha Bay sightseeing fee (usually in boat price); national park entrance and guide fees for the trek |
| Time needed | About 45–60 minutes by boat; a full day on the trek |
| Best time | March–May and September–November |
| Nearby | Viet Hai Village, Trung Trang Cave, Dark and Bright Cave |
| Find it | Google Maps · UNESCO · Cat Ba National Park on Wikipedia |
Is Ao Ech Area Worth Visiting?
Yes, if you enjoy quiet nature. By boat, Ao Ech is a peaceful pause between livelier stops; on foot, the Frog Lake is the halfway highlight of one of Cat Ba’s best forest treks. Neither is a big headline sight, so plan it as part of a Lan Ha day or a national park hike.

- Best for: nature lovers, hikers and travellers seeking calm.
- Skip if: you want famous caves or beaches; head to Halong Bay or Cat Ba’s beaches.
- Short on time: choose a Lan Ha day boat that includes it with other stops.
Background of Ao Ech Area
“Ao Ếch” means “frog pond” or “frog lake”. The best-known Ao Ech is a lake in the limestone forest of Cat Ba National Park, created in 1986 and the first protected area in Vietnam with a marine zone. In Lan Ha Bay, enclosed or sheltered waters between karst towers, typical of the Cat Ba Archipelago, are used as calm stops by boats. Since 2023 the archipelago has been part of the UNESCO World Heritage Site Ha Long Bay – Cat Ba Archipelago, and since 1 July 2025 it has been governed by the Cat Hai Special Zone of Hai Phong city.
What to See at Ao Ech Area
1. The Lan Ha Bay Lagoon
Calm water ringed by steep green cliffs, best seen from a small boat in the morning when the surface is still.
2. Karst Cliffs and Birdlife
Look for hanging vegetation, wave-cut notches and birds nesting on the cliffs.
3. Frog Lake in Cat Ba National Park
On the trek from the park’s forest trails towards Viet Hai, Frog Lake is a quiet forest lake whose water level varies with the season; it is fullest after the summer rains.
4. The Trek to Viet Hai
The full-day hike continues downhill to Viet Hai Village, from where boats return to Cat Ba town across Lan Ha Bay.
Fees and How to Visit
| Item | Detail |
|---|---|
| Lan Ha Bay sightseeing fee | Set by Hai Phong city; usually included in boat and cruise prices |
| Small-boat / kayak visits | Only with licensed operators when permitted |
| National park trek | Park entrance ticket (160,000 VND per adult, 80,000 VND per child aged 6+) plus a licensed guide (recommended) |
- Decide whether you want the boat stop (Lan Ha) or the trek (national park), or both.
- For the boat, book a licensed Lan Ha day trip and confirm what activities are allowed.
- For the trek, arrange a guide in Cat Ba town or at the park headquarters and book the boat back from Viet Hai.
How to Get to Ao Ech Area
| From | How | Time |
|---|---|---|
| Ben Beo Pier (Cat Ba town) | Lan Ha day boat | About 1 hour sailing |
| Cat Ba National Park HQ (Trung Trang) | Guided trek towards Viet Hai | A full day including the boat back |
| Hanoi | Road + ferry to Cat Ba | About 3–3.5 hours |
See our Cat Ba Island guide for transport to the island.
Best Time to Visit Ao Ech Area
| When | What to expect |
|---|---|
| March–May | Mild weather, good for trekking and boating |
| June–August | Hot and humid; heavy rain makes trails slippery; storms can cancel boats |
| September–November | Comfortable and clear; Frog Lake still full after the rains |
| December–February | Cool and misty; the lake can be low |
Local Expert Tips for Ao Ech Area
These tips come from years of arranging Halong and Lan Ha tours for international travellers.
- Clarify which Ao Ech your tour visits: the bay stop or the forest lake.
- Wear proper hiking shoes for the trek and carry plenty of water.
- Do not trek alone; trails in the park are not always clearly marked.
- Read our Halong travel tips and cruise guide before booking.
Ao Ech Area vs Dark and Bright Cave
| Ao Ech Area | Dark and Bright Cave | |
|---|---|---|
| Experience | Open, calm water or forest lake | Low tunnel into a hidden lagoon |
| Effort | Easy by boat; strenuous on foot | Small boat through a tunnel |
| Crowds | Low | Moderate |
Our view: Dark and Bright Cave is more dramatic; Ao Ech is calmer and, on foot, part of a great day hike.
Nearby Attractions
- Viet Hai Village – cycling valley at the end of the trek.
- Trung Trang Cave – near the park headquarters.
- Dark and Bright Cave and Ba Trai Dao Islets – in Lan Ha Bay.
- Lan Ha Bay and Cat Ba Island.
Halong Area for First-Time Visitors: Where Ao Ech Area Fits
After Hanoi, spend two nights on Cat Ba: one day on Lan Ha Bay and one day trekking past Frog Lake to Viet Hai.
Plan your trip with our Halong Bay travel guide and Halong Bay and Lan Ha tours. Contact Vietnam Tour Expert Team for a free custom itinerary.
Frequently Asked Questions about Ao Ech Area
1. What is Ao Ech Area?
Ao Ech Area (“Frog Lake”) refers to a calm boat stop in Lan Ha Bay and the Frog Lake in Cat Ba National Park on the trek to Viet Hai.
2. Where is Ao Ech Area?
Ao Ech Area is around Cat Ba Island in Hai Phong: in Lan Ha Bay east of the island and in the national park forest.
3. How do I get to Ao Ech Area?
Reach the Lan Ha Bay Ao Ech Area by day boat from Ben Beo Pier, or the Frog Lake on a guided trek from the national park headquarters.
4. Can I kayak at Ao Ech Area?
Kayaking in the Cat Ba bays, including Ao Ech Area, was suspended in November 2024; ask whether licensed kayaking has resumed.
5. Is there a fee for Ao Ech Area?
The Lan Ha Bay fee covers the boat stop at Ao Ech Area; the trek requires a national park ticket and guide.
6. How hard is the trek to Ao Ech Area?
The trek to Ao Ech Area (Frog Lake) is a full-day forest hike with uneven, sometimes muddy trails.
7. Do I need a guide for Ao Ech Area?
A licensed guide is strongly recommended for the Ao Ech Area trek in Cat Ba National Park.
8. What is the best time to visit Ao Ech Area?
March–May and September–November are the best months for Ao Ech Area.
9. Is Ao Ech Area part of the UNESCO site?
Yes. Ao Ech Area lies within the UNESCO site Ha Long Bay – Cat Ba Archipelago.
10. Is Ao Ech Area suitable for children?
The boat stop at Ao Ech Area suits children; the full-day trek suits older, fit children only.
11. How long does a visit to Ao Ech Area take?
A boat stop at Ao Ech Area takes about 45–60 minutes; the trek takes a full day.
12. Can I combine Ao Ech Area with Viet Hai Village?
Yes. The trek past Ao Ech Area ends at Viet Hai Village, with a boat back to Cat Ba.
13. Is Ao Ech Area crowded?
Ao Ech Area is usually quiet compared with Lan Ha Bay’s beaches and caves.
14. Does Ao Ech Area have water all year?
The forest Frog Lake at Ao Ech Area is fullest after summer rains and can be low in the dry season.
15. What is near Ao Ech Area?
Near Ao Ech Area are Viet Hai Village, Trung Trang Cave and Dark and Bright Cave.




























