The spectacular islands of Bai Tu Long Bay, immediately northeast of Halong Bay, form Bai Tu Long National Park and are every bit as beautiful as their famous neighbour. In some ways the park is actually more stunning, since it’s only in its early stages as a destination for travellers. The bay and its islands are still unpolluted and relatively undeveloped.
As with Halong Bay, the best way to experience the full limestone-pinnacle-scattered seascape is on a cruise, though there are relatively few outfits that tackle the area. Hanoi-based companies such as Ethnic Travel (www.ethnictravel.com.vn), do overnight trips; alternatively, Cat Ba Ventures can organise a custom tour.