Tourism in West Bengal is in the South Asia region of Bengal, consisting of West Bengal and its neighbouring country of Bangladesh. It is the world's largest delta, and empties into the Bay of Bengal. It is one of the most fertile regions in the world, thus earning the nickname "The Green Delta". It stretches from the Hooghly River on the west to the Meghna River on the east. It is approximately across at the Bay of Bengal. Kolkata and Haldia are the principal Indian seaports on the delta. The Acharya Jagadish Chandra Bose Indian Botanic Garden or Calcutta Botanical Garden (previously known as
Tourism in West Bengal which is 13.38% of the state's geographical area, compared to the national average of 21.02%. Part of the world's largest mangrove forest, the Sundarbans, is located in southern West Bengal. The southern part of West Bengal can be divided into two regions: the Gangetic plain and the littoral mangrove forests of the Sundarbans. The coastal region of Purba Medinipur exhibits coastal vegetation. A notable tree from the Sundarbans is the ubiquitous "sundari" ("Heritiera fomes"), from which the forest gets its name. The distribution of vegetation in northern West Bengal is dictated by elevation and precipitation. For example, the foothills of