Ha Long Bay has long ago due to tectonic. However, in the minds of the Vietnamese people from prehistoric times to the popular imagination and the idea of Dragon and Fairy roots, some legends that when the English founded the country were foreign invaders , Jade Emperor sent Mother Dragon and her child Dragons down to earth to help the Viet people fight the invaders. Marine invaders’ boats were rushing to the shore just as the dragons landed down on earth. The dragons immediately ejected the enemy boat burned, partially Chau Ngoc Dung imposing stone walls make the enemy hit that broke the boat, stop the progress of the Gentiles.
After the victory, the ground peaceful, lush trees, the people here diligence, hard work, solidarity and help each other, Mother Dragon and Child Dragons did not return Heaven but stayed on earth, where just place the eternal battle to protect the people of Dai Viet. Location Mother Dragon landed was Ha Long; where Child Dragons came down was Bai Tu Long and the water dragon undo tail is white Bach Long Vi (Tra Co Peninsula today, with over 15 km long sandy beach).
Other legends say that at a time when a country with invaders, a dragon flying along the river down to the sea and landed in the coastal Northeast make sure bulwark step of aquatic invaders. Dragon landed sheltered accommodation for the country known as Ha Long.