Sundarbans National Park is a national park, tiger reserve and biosphere reserve in the South 24 Parganas district of the Indian state of West Bengal. The Greater Sundarbans is the largest mangrove forest in the coastal saline environment, with the largest forest in the world [1]. The coastal boundary of the basin is located at the mouth of the Ganges and Brahmaputra and extends across West Bengal in Bangladesh and India. The Sundarbans covers an area of 10,000 sq km and covers about 6,016 sq km in Bangladesh [2]. Tides up to 75 m in the Bay of Bengal are always seen here. In 18 AD, the conservation work of the present Indian part of the Sundarbans began. In 1983, the main area was declared the Sundarbans Tiger Reserve. In 1987, the 133,000-hectare main area of the 256,500-hectare Sundarbans Tiger Reserve was declared a wildlife sanctuary. It was declared a national park on May 4, 1984. In 1986, it was declared a UNESCO World Heritage Site as a natural property in (ix) and (x) categories. [3] There are now three more wildlife sanctuaries at Sajanekhali, Luthian Island and Holiday Island. Besides, there is Bharatpur Crocodile Project near Patharpratima and Bird Sanctuary at Sajnekhali. This Indian part of the Sundarbans was declared a biosphere reserve in 1989.