Sundarbans East Wildlife Sanctuary, a protected forest in Bangladesh, extends over an area of 31,227 ha. of mangrove forest. It was established in 1977 under the Bangladesh Wildlife (Preservation) (Amendment) Act, 1974, having previously been a forest reserve. It is the most fertile of the three, non-adjoining wildlife sanctuaries established in the Sundarbans at that time, the others being the Sundarbans West Wildlife Sanctuary and the Sundarbans South Wildlife Sanctuary. The dominant mangrove species is "sundri" (Heritiera fomes) from which the Sundarbans region gets its name.