Thien Canh Son Cave, Halong Bay: 2026 Guide to Hang Co, Its Beach & How to Visit

By Jimmy, Halong Bay cruise specialist · Updated 9 October 2026

Thien Canh Son Cave 2026: Eastern Halong Bay’s Quiet Cave, Viewpoint and Beach

Thien Canh Son Cave, known locally as Hang Co (Grass Cave), is on Hon Co island in the quieter eastern part of Halong Bay, about 19 km from Tuan Chau and 14 km from Ha Long International Cruise Port. A narrow entrance opens into chambers of golden-brown stalactites lit by shafts of daylight, a rear path leads to a viewpoint, and a small beach lies below. It is on official route VHL4 and is a regular stop on cruises sold as Bai Tu Long Bay trips.

Good to know (checked October 2026): Although many cruise companies call this area Bai Tu Long Bay, Quang Ninh’s official route list places Thien Canh Son on Halong Bay route VHL4, managed by the Ha Long Bay Management Board. It is much smaller than Sung Sot Cave; the appeal is the quiet. Steps can be slippery after rain.

Thien Canh Son Cave at a Glance

Location	Hon Co island, eastern Halong Bay, near the Cong Do area; route VHL4
Distance	About 19 km from Tuan Chau; about 14 km from Ha Long International Cruise Port
Name	Thiên Cảnh Sơn means mountain with a view of fairyland; local name Hang Cỏ, Grass Cave
Character	Narrow entrance, wide interior, golden-brown stalactites, light shafts, rear viewpoint
Visit time	30–45 minutes for the cave, plus beach time
Extras	Small beach on the island for swimming and kayaking in warm months
Route	VHL4 with Hang Thay, Cap La, Vung Vieng, Tung Ang, Cong Do and Hon Xep
Ticket	VHL4 route ticket (200,000 VND, Management Board 2025); included in our cruise prices
Find it	Google Maps · TripAdvisor

Is Thien Canh Son Cave worth it? Yes as part of an eastern-bay cruise, for the calm, the light inside and the view; no as a destination on its own. Pair it with kayaking and a bamboo boat ride at Vung Vieng.

Thien Canh Son Cave interior — stalactite formations resembling lotus flowers and chandeliers, Bai Tu Long Bay's most spectacular cave, Vietnam — Stalactites inside Thien Canh Son Cave in eastern Halong Bay

What Makes Thien Canh Son Cave Special

Almost no crowds

The eastern bay receives a fraction of the boats that crowd route VHL2, so you often share the cave with one small group or none.

Light from above

Openings in the ceiling let shafts of daylight fall onto golden-brown formations, which gives the cave a softer feel than the colour-lit show caves.

Cave, view and beach in one stop

A short loop ends at a rear exit with a view over the islands, then you can swim or kayak from the beach.

Gateway to the Cong Do area

The cave lies close to Cong Do, one of the bay’s main coral areas, where the Management Board records reef cover of 30–45%.

Story and Name

Fishermen knew it as Hang Cỏ, the Grass Cave, after the vegetation around its entrance. When it was opened to visitors it was renamed Thiên Cảnh Sơn, mountain with a view of fairyland. Its discovery date and exact dimensions have not been published. Before protection some formations were broken off by collectors, which is why parts of the cave look bare. Background is on the Management Board page and the Showcaves database.

Panoramic view of Bai Tu Long Bay from Thien Canh Son Cave's entrance viewpoint — limestone islands and emerald water, Cong Do Nature Reserve, Vietnam — The bay view from the rear exit of Thien Canh Son Cave

What to Do at Thien Canh Son Cave

1. Walk the chambers

A path of steps leads through the narrow entrance into a wider chamber; the walk takes about 30 minutes at a relaxed pace.

2. Take in the view

The rear path faces the bay and the surrounding islets, a good photo spot in late afternoon.

Secluded white-sand beach at the base of Hon Co Island below Thien Canh Son Cave, Bai Tu Long Bay Vietnam — The small beach below Thien Canh Son Cave on Hon Co island

3. Swim or kayak at the beach

The small beach at the foot of the island is used by cruises for swimming and kayaking from about May to October.

Tickets and Practical Information

Item	Details (checked October 2026)
Hours	Daytime; visits timed by cruise itineraries
Ticket	VHL4 route ticket (200,000 VND on the Management Board’s 2025 list), included in cruise prices
Access	Steps from the jetty and inside; not wheelchair accessible
Rules	No touching formations; no litter or single-use plastic

How to Get to Thien Canh Son Cave

Option	How it works	Notes
Eastern bay / Bai Tu Long cruise (2D1N or 3D2N)	Usually an afternoon or morning stop with Vung Vieng	Best way
VHL4 day boat	About 8 hours from the port	Long day
Private boat	Ask us	Flexible timing

Best Time to Visit

Months	Conditions
March–May	Mild, calm
June–August	Hot; swimming; storm risk
September–November	Clear and pleasant
December–February	Cool, misty; steps can be damp

See the best time to visit Halong Bay.

Thien Canh Son Cave vs Sung Sot Cave

	Thien Canh Son	Sung Sot
Area	Eastern Halong Bay (VHL4)	Central Halong Bay (VHL2)
Size	Small to medium	Very large, about 10,000 m²
Lighting	Mostly natural light	Colour lighting
Crowds	Very few	Busy
Extras	Beach and kayak	Ti Top and Luon nearby

Our view: If you want the grand cave, choose a route with Sung Sot Cave. If you want quiet water and space, the eastern bay with Thien Canh Son Cave wins.