Description : Fishing boats on the Poshur River at Mongla, the entrance point of the Sundarbans. A UNESCO World Heritage Site, it is the largest littoral mangrove forest in the world. The area is known for its wide range of fauna, including 260 bird species, the Royal Bengal tiger and other threatened species such as the estuarine crocodile and the Indian python. Khulna, Bangladesh. March 28, 2009.