Appeared in the first epoch as a huge limestone scattered in the delta of the Red River full of alluvium and located in Quang Ninh province abundant in open coal mines, Ha Long Bay looks like a paradise due to its charm and beauty. Ha Long Bay is a bay in the Gulf of Tonkin comprised of regions of Ha Long City, the township of Cam Pha, and a part of the island district of Van Don. Ha Long Bay borders Cat Ba Island in the southwest, the East Sea in the east, and the mainland, creating a 120 km coastline.

Legends said that a huge dragon and its children descended there to help the Vietnamese fight against the Northern invaders. After the victory, these dragons decided to stay with the local people. Since then this area has been called the " descending dragon" region. The local junks moving gently along the islets in the sunset bring a strange experience.

With its 3,000 islands on an area of 1,500 km2 rising from the crystalline emerald waters of the Gulf of Tonkin, the Ha Long Bay has been a major attraction for tourists and film makers alike. It is one of the natural wonders of Viet Nam and is now listed as a World Heritage site.

Ha Long Bay affords some of Vietnam's most spectacular scenery, including beautiful limestone formations, rock arches, gin-clear water, virtually scenery lagoons, eerie caves, peaceful coves, sheer cliffs, secluded strips of white, powdery sand, and thousands of limestone islets. Like sculpted cartoon characters, these islets are fancifully named: Frog Island, Face Island, Isle of Surprise, etc. Among thousands of caves of all sizes and shapes, Hang Dau Go (Grotto of Wooden Stakes), known to the French as the Grotte des Merveilles (Cave of Marvels) is a huge one consisting of three chambers which you reach via 90 steps. Among the stalactites of the first hall, scores of gnomes appear to be holding the meeting. The walls of the second chamber sparkle if bright light is shined on them. The cave derives its Vietnamese name from the third of the chambers, which is said to have been used during the 13th century to store the sharp bamboo stakes, which Tran Hung Dao planted in the bed of the Bach Dang River to impale the Kublai Khan's invasion fleet. Other well-known caves in Ha Long Bay include the Grotto of Bo Nau and 2 km long Hang Hanh Cave.