The Sundarbans are the largest continuous mangrove forests in the world, covering about 6,000 sq. km of both land and water. Part of the world's largest delta formed by the great Ganges and Brahmaputra rivers, which converge on the Bengal basin. The western portion lies in India and the rest (about 60%) in Bangladesh. About one third of the total area of this forest is covered by river channels, canals and tidal creeks, varying in width from a few meters to five kilometers. The Bangladesh portion of the forest is dominated by high mangroves, the climate is tropical maritime, with lots of rain during the monsoon. During the winter it is mild and dry.

The National Park area is home to a wide variety of mangrove and other flora as well as many species of fish, birds and mammals. This is home to the Royal Bengal tiger (a rarity), as well as Rhesus macaques,clawless otters, leopard cats, fishing cats, spotted deer. In the water are found river dolphins, fifty species of reptiles and eight species of amphibians and the only population of the estuarine, or saltwater crocodile in Bangladesh..