Recommended by some friends, we had booked a fancy cruise on a traditional vietnamese junk. This Unesco-classified scenic landscape actually covers 3 bays (Halong, Bai Tu Long and Lan Ha). We went on the second one (Bai Tu Long bay) which is less touristic while offering a similar karst scenery. Though we were hesitating a bit before booking it as it was quite expensive, we must admit we were not disappointed in any way.