Hidden among the thousands of jungle-covered peaks rising dramatically out of the emerald waters of Ha Long Bay are illuminated caves, isolated grottos and picturesque hidden coves of all shapes and sizes.

Dau Go is one of the most beautiful cave at Ha Long. The name, Dau Go or Giau Go, has direct ties to the history of Vietnam. According to the locals, while preparing for the Mongolian attacks in 1288, general Tran Hung Dao, sent a convoy to this area to cut wood from this region. Wooden stakes were then fashioned from the wood and hidden in Dau Go cave. The stakes were embedded in Bach Dang river to form a barrier against the attacking Mongols.

Thien Cung Cave (Heavenly Palace Cave) is located in the southwest of Ha Long Bay, 4 km away from Dau Go Island, which is considered the most beautiful primitive cave of the Bay. The cave is 10,000 square meters with complicated interior structure, many floors, and high ceiling. The cave becomes famous thanks to a unique system of stalactites and stalagmites with different forms and shapes.

Both of these caves are included in cruising routes of Ha Long Bay tours.