Description : Tourists watch wildlife ride on a boat in a winter morning in Sundorbans, the 798th World heritage site declared by UNESCO. It is the largest littoral mangrove forest in the world. The Sundarbans cover an area of 38,500 sq km, of which about one; third is covered in water. Since 1966 the Sundarbans have been a wildlife sanctuary, and it is estimated that there are now approximately 400 Royal Bengal tigers and about 30,000 spotted deer in the area. Sundarban, Khulna, Bangladesh.