Children's poem Motibil from the collection Chitra by Rabindranath Tagore. A unique feature of the landscape of the alluvial Bengal is the existence of a large number of bils or marshy areas. Lower Bengal was created out of the Bay of Bengal entirely by the great river systems of the Ganges and the Brahmaputra with their huge quantity of silt deposited over a very long time. In this process many areas remained unfilled and thus these bils with unique ecology were born. While managing his ancestral zamindari in North Bengal Tagore found many such bils. His description of
a bil in this short lovely poem written for children is perhaps the best.