The Sundarbans is a mangrove forest extending from Bangladesh into the hinterlands of West Bengal, India. It has been named as a World Heritage Site by UNESCO. The forest is thick and the area, covered with marshy swamps and salt water. It is home to the Royal Bengal Tiger, of which only 400 are left here. Crocodiles, spotted deers, snakes, primates and many different species of birds can be seen here. Tourists need to have a permit to visit the Sunderbans especially the Tiger Reserve.