Sundarban is the largest delta, largest tidal mangrove forest and only mangrove tiger land in the world. Sundarban is the home of approx. 85 species of true, back and associate mangroves, 58 species of mammals and 248 species of birds. It was declared as World Heritage Site by UNESCO in 1987. The geographic location of Sundarban is the south tropical cancer 21º31’ and 22º 31’ in the north and 88º10’ and 89º51’ in the east. The delta formed by the confluences of Ganga, Brahmaputra and Meghna rivers across south Bangladesh and West Bengal, India. The total area of present Sundarban forests is 10,263 km² of which 60% lies on Bangladesh and 40% in India, West Bengal. In Indian part there are 104 islands of which 54 islands are inhabited. The area is crisscrossed by seven major rivers (Raimangal, Harinbhanga, Gosaba, Matla, Bidyadhari, Thakurine and Saptamukhi) along with innumerable rivulets and tidal creeks form the rich vegetation and diverse mangrove forest. Sundarban Tiger Reserve was established in the year 1973 under “Project Tiger” by the Ministry of Environment & Forests, Govt of India. Sundaban Biospnere Reserve was declared as Biosphere Reserve (Man and Biosphere) by UNESCO in 1989. There are three Sanctuaries and one National Park located within the Sundaban Biosphere Reserve (9,630 km²) are: Sundarban National Park (1,330 km²), Sajnekhali Wildlife Sanctuary (362 km²), Lothian Island Wildlife Sanctuary (38 km²) and Haliday Island Wildlife Sanctuary (6 km²). Core area of Sundarban National Park (1,330 km²) was created in the year 1987. Currently, the core area has been expanded to 1699 km².