Luon Cave is located in the northeast of Bo Hon Island. It's about 14 kilometers to the south from Bai Chay Beach. Near the cave are Con Rua Islet (Turtle Islet) and Sung Sot Cave (Surprise Cave).
Luon Cave is about 60 meters long and 4 meters wide. Height of the ceiling ranges from 2.5 – 4 meters up on tidal level. Therefore, it only can be accessed by small boat or kayak.
Passing through Luon Cave, tourists will reach a lake formed by an enclosed group of lime-stone mountains. The lake inside seems like a stadium surrounded by high podium. It’s a brackish lake with calm and green sea water. Size of the lake is nearly 1 square kilometers. On the cliff are many fossilized freshwater snail shells proving that place used to be a deep freshwater valley. Especially, it’s highlighted with pristine setting of ferns, orchids and wild golden monkeys.
The perfect combination of lime-stone mountains and jade-green sea makes Luon Cave a unique site to visit on Halong Bay. Furthermore, Luon Cave is a preferred place of tourists for kayaking.