There's more to northeastern Vietnam than Halong Bay. The sinking limestone plateau, which gave birth to the bay's spectacular islands, continues for some 100km to the Chinese border. The area immediately northeast of Halong Bay is known as Bai Tu Long Bay. With long and smooth sand banks and clear water waves, Bai Tu Long Bay is associated with the graceful and sweet beauty of a teen-aged girl.

The bay also attracts a growing number of domestic and foreign visitors to its historical and cultural sites, rare and precious specialties, and the archipelago's unspoiled beauty.

There is a legend about the archipelago that in the old days when the Vietnam was attacked by foreign invaders, the God sent a mother dragon and its babies to support the Vietnamese people. The dragons immediately blew out myriad pearls and gems that turned into grand rock mountains as a solid citadel to protect the Vietnam. After the foreign invaders were pushed away, the mother dragon and its babies did not return to the heaven but stayed in the lower world. The land where the mother dragon landed was then called Ha Long, and where the baby dragons landed called Bai Tu Long. The area where the dragon tails lashed was called Long Vi, nowadays Tra Co Peninsula, which consists of many long and smooth sand banks.

There are hundreds of islets rising from the water and many quirkily shaped rock mountains on Bai Tu Long Bay's site. Touring Bai Tu Long Bay, a day is not enough for visitors to discover these mysterious islets. Bai Tu Long National Park can also bring great surprises, and is one of the most desirable stopovers for visitors making a trip to Bai Tu Long Bay.