The Venetian Plain, or Venetian-Friulan Plain is a major geographical feature of Italy. It extends approximately from river Adige to river Isonzo, in an southwest-to-northeast direction, including almost all the flatlands of Veneto and Friuli. It is not properly related to the Po River basin, but it is often considered as a part of Po Valley since the flatlands of Veneto and Friuli do not drain into the Po, but they effectively combine into an unbroken plain. Sometime, instead of Adige river, the Euganei Hills and Berici Hills are considered to be its western border.