The river Ill rises in the Jura mountains of Alsace and flows across the Alsatian plain. It is more than 200 kilometres long and passes through Bas-Rhin and Haut-Rhin. The river Ill flows through Mulhouse, Colmar and Strasbourg. Within the city of Strasbourg it traverses the picturesque area known as "La Petite France". The Ill has many tributaries and is generally higher in winter than in summer. It is a large river because it is fed by precipitation on the Vosges mountains.