The mouth of Bo Nau Cave is quite wide with the size of 5-7 meters. It’s in the shape of arch and has many stalactites falling down from the ceiling. Right on the entrance is three blocks of stone. They look like a sculpture about three fairies playing chess. The space inside covers an area of 200 square meters. The foundation of Bo Nau Cave is flat with various stalagmites growing up in different sizes and shapes.
From the cave, tourists will get a unique view of Halong bay that seems like standing in the monster’s mouth with sharp teeth and seeing magnificent scenery outside.