The Sunderbans, extending over an area of 1,000,000 hectares, is the world's largest delta, formed by the Ganges, Brahmaputra and Meghana rivers. The region has extensive mangrove forests and the contours are in a constant state of flux, caused by the monsoon flooding each year. It was declared a national park in 1984. A majority of the park is at sea level and the higher grounds range in altitude from a mere 6 - 9 meters. The park is surrounded by a buffer zone of 885 square kilometers. 

This also mainly consists of mangrove forests. The core area of the park has it's own natural boundaries with the river Matla on it's West, the river Haribhanga on it's East, with Netidhopani and Gosba in the North.
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Flora in Sunderbans National Park Fascinating life forms await you in this largest estuarine delta in the world, Sunderbans. In April and May the flaming red leaves of the Genwa, edge the emerald islands. The crab like red flowers of the Kankara and the yellow blooms of Khalsi add to the dazzling display. As you penetrate into the forests of Sundarbans, this fairyland unfolds its mysterious beauty. aaa Major Wildlife Attractions of Sundarban The Sundarbans forest is home to more than 400 tigers. The Bengal Tigers have adapted themselves very well to the saline and aqua environs and are extremely good swimmers. As you enter the adventurous wild land of the Sundarbans you'll be thrilled to see the Chital Dear and Rhesus Monkey. The aqua fauna of Sundarbans include variety of fishes, red Fiddler Crabs and Hermit Crabs. There are crocodiles, which can be often seen along the mud banks. Sundarbans national park is also noted for its conservation of the Ridley Sea Turtle. There's is a incredible variety of reptiles also found in Sundarbans, which includes King Cobra, Rock Python and Water Monitor. The endangered river Terrapin, Batagur Baska is found on the Mechua Beach, while the Barkind Deer is found only in Holiday Island in Sunderbans. aaa Best Time to Visit Sundarbans National Park The best time to visit the park is between December and February, although the park is open for longer from September to March. This is the period when the maximum migratory birds are also present here.