Meanders:
Meanders are formed curves and bends that is noticeable along the river course as a result of a river flowing over flat land. They are formed when the river erodes sideways and deposits the sediments it is carrying on the opposite sides of the curves. 

http://en.wikipedia.org/wiki/File:Tournon_-_confluent_du_Doux_avec_le_Rhône_.JPG

-Gracia-