Halong Bay is one of the great travel clichés of Southeast Asia — and clichés exist for good reason. The UNESCO World Heritage Site's 1,969 limestone karsts rising from jade-green water is genuinely one of the most extraordinary landscapes on earth. But it is also genuinely crowded. On peak season mornings, dozens of cruise boats jostle for the same sunrise photograph at the same iconic viewpoints.

Lan Ha Bay is the answer. Part of the same geological formation, lying just south of Halong's boundary, it sits within Cat Ba National Park. The scenery is equally dramatic — arguably more so in places, with wilder, less manicured shorelines — but the boat traffic is perhaps a tenth of Halong's. You can anchor in a calm lagoon and not see another vessel for hours.

The Case for Halong Bay

Halong's infrastructure is more developed, which means a wider choice of high-quality junk boats. The Heritage Line, Indochine Sail, and L'Azalée represent the pinnacle of the cruise experience: beautifully designed vessels with excellent kitchens, attentive service, and well-planned excursion programmes. The iconic viewpoints — Fighting Cocks Islets, Surprising Cave, the floating fishing village of Cua Van — are iconic for a reason. First-time visitors, or those visiting with family members who prioritise comfort over adventure, will likely prefer the Halong experience.

The Case for Lan Ha Bay

Lan Ha is for travellers who want genuine discovery. The kayaking routes through hidden lagoons are more varied and less trafficked. The swimming is better — cleaner water, fewer boats, more privacy. The Cat Ba Island harbour town, while not especially pretty, has an authentic fishing community energy that Halong's tourist-facing port towns have largely lost. If you are a second-time visitor, or if you prioritise solitude and nature over comfort and convenience, Lan Ha is the correct choice.

The Best Answer: Two Nights Covering Both

The finest itinerary combines both bays in a single cruise: depart Tuan Chau port (Halong), spend the first day and night in Halong Bay's classic highlights, then sail south through the boundary into Lan Ha Bay for day two and night two. This gives you the iconic Halong sunrise and the peaceful Lan Ha anchorage. A handful of premium operators, including Heritage Line, run exactly this route. Book it for two nights minimum — one night is not enough on either bay.

Our recommendation: The Heritage Line Jasmine or Indochine Sail's Au Co, two nights, combining both bays, departing Sunday or Monday when weekend traffic has cleared.