Situated on the southwest side of Halong Bay, Ba Ham Lake is found on Dau Be Island (Calf Head Island) in Lan Ha Bay – Cat Ba Vietnam. This island is part of the range of islands at the farthest end of Halong Bay, bordering the immense zone Long Chau Sea.

Ba Ham Lake – actually is a lagoon or a “funnel” – a form of geomorphic karst terrain typical of Halong Bay. Ba Ham Lake belongs to Dau Be island chain, adjacent to Cat Ba Island, Lan Ha Bay. This is one of the three triangular peaks in the absolute protected area of World Natural Heritage Halong Bay. Ba Ham Lake consists of 3 large lakes connected by 3 caves (tunnel), hence the name is Ba Ham Lake (Three Tunnel lake).

Ba Ham Lake still retains the mystical wild beauty because there is no human impact or existence of any construction. Visitors want to explore the beauty of Ba Ham Lake can only use bamboo boat or kayak to row through the caves to enter the lakes at low tide. The entrance to Ba Ham Lake is not as easy as in Luon Cave, but it is the exciting experience of the sightseeing. The semi-circular cave opens on a flat cliff in the northwestern of the island, 4 – 5m from the water surface. Leading to the first lake is a stone cave which is 150m long, 10m wide, the highest ceiling is up to 2m. On the right side, you find the way to the second lake, which is about 60m in length. The second lake is the largest one among three lakes, with an area of about 1,000m2. From the first one, through the 60m underground cavern on the left side is the third lake which is about 600m2.

In Ba Ham Lake, four sides are surrounded by mountains, the space is completely quiet, only the birds sing in the harmony with blue sky and emerald Halong water. The deeper, the darker. Through the dim dark caves, each cluster of stalactites hanging down from the ceiling with strange shapes appears in your eyes. Along the way, sometimes you might think that there is a retaining rock wall in front since all space is covered by dark black, but if the paddle continues, small light streams begin to appear, leading you to a new scenery. Some places are very wide but some are really narrow; some are noisy but some are quiet; such a harmony landscape nature.

Ba Ham Lake is a favorable condition for the animals and plants to live and develop. On the limestone cliffs around the lake, visitors can see a green color of tropical vegetation, very rich in species. Notably, Ba Ham Lake is home to three endemic species of Halong Bay, namely the Paphiopedilum Concolor, Livistona halongensis and Halong fern. In addition, Dau Be Island is the habitat of golden hair monkeys. So do not be surprised to see a few monkeys hiding on the cliffs around. Besides the monkey, around Ba Ham Lake also have mink, squirrels, some birds … The third cave has many butterfly bats, under the blue water is the vibrant life of many marine species. There are many bamboo boats waiting at the door to bring visitors into the lake, each carrying 6-7 people.