The Ill is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in Alsace

Alsace

Alsace is the fifth-smallest of the 27 regions of France in land area , and the smallest in metropolitan France. It is also the seventh-most densely populated region in France and third most densely populated region in metropolitan France, with ca. 220 inhabitants per km²...

, in north-eastern France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

. It is a left-side, or western tributary of the Rhine.

It starts down from its source near the village of Winkel

Winkel, Haut-Rhin

Winkel is a commune in the Haut-Rhin department in Alsace in north-eastern France.The village is known in Alsace as the Ill river takes its source. Its inhabitants are called Winkelois and Winkeloises.-References:*...

, in the Jura mountains

Jura mountains

The Jura Mountains are a small mountain range located north of the Alps, separating the Rhine and Rhone rivers and forming part of the watershed of each...

, with a resurgence near Ligsdorf

Ligsdorf

Ligsdorf is a commune in the Haut-Rhin department in Alsace in north-eastern France.-References:*...

, turns around Ferrette

Ferrette

Ferrette is a commune in the Haut-Rhin department in Alsace in north-eastern France.It is situated close to the Swiss border. Its main attraction is the Château de Ferrette.-County of Ferrette:...

 on its east side, and then runs northward through Alsace, flowing parallel to the Rhine. Taking apart the Largue, also coming from the Jura mountains near Illfurth

Illfurth

Illfurth is a commune in the Haut-Rhin department in Alsace in north-eastern France.-References:*...

, it receives several tributaries from the west bank Vosges mountains

Vosges mountains

For the department of France of the same name, see Vosges.The Vosges are a range of low mountains in eastern France, near its border with Germany. They extend along the west side of the Rhine valley in a northnortheast direction, mainly from Belfort to Saverne...

 after passing through Altkirch

Altkirch

-See also:* Château d'Altkirch - destroyed castle in the town.* Communes of the Haut-Rhin department-References:* -External links :* * * * * * * *...

: the Doller in Mulhouse

Mulhouse

Mulhouse |mill]] hamlet) is a city and commune in eastern France, close to the Swiss and German borders. With a population of 110,514 and 278,206 inhabitants in the metropolitan area in 2006, it is the largest city in the Haut-Rhin département, and the second largest in the Alsace region after...

, the Thur

Thur (France)

The Thur is a river in the Haut-Rhin department, Alsace, France, left tributary of the river Ill. It rises in the Vosges Mountains, and flows through the towns Thann and Cernay. It flows into the Ill near Ensisheim, north of Mulhouse.-References:*http://www.geoportail.fr*...

 near Ensisheim

Ensisheim

Ensisheim is a commune in the Haut-Rhin department in Alsace in north-eastern France.On 7 November 1492, a 250 pound meteorite fell there, and since then it has attracted many meteorite enthusiasts. It was described in detail by the contemporary poet Sebastian Brant.Ensisheim is also the birthplace...

, the Lauch in Colmar

Colmar

Colmar is a commune in the Haut-Rhin department in Alsace in north-eastern France.It is the capital of the department. Colmar is also the seat of the highest jurisdiction in Alsace, the appellate court....

, the Fecht in Illhaeusern

Illhaeusern

Illhaeusern is a commune in the Haut-Rhin department in Alsace in north-eastern France.In the middle of the village, the river Ill receives the Fecht.Illhaeusern is famous for the Auberge de l'Ill, still one of the oldest 3-star establishments in France....

, the Giessen in Sélestat

Sélestat

Sélestat is a commune in the Bas-Rhin department in Alsace in north-eastern France.In 2006, Sélestat had a total population of 19,459. The Communauté de communes de Sélestat et environs had a total population of 35,397.-Geography:...

, the Andlau near Fegersheim

Fegersheim

Fegersheim is a commune in the Bas-Rhin department in Alsace in north-eastern France.-Geography and Economics:Fegersheim is located to the south of Strasbourg, between the Rivers Andlau, Scheer and Ill....

, the Ehn near Geispolsheim

Geispolsheim

Geispolsheim is a commune in the Bas-Rhin department in Alsace in north-eastern France.-Geography:Geispolsheim is positioned to the south of Strasbourg....

, the Bruche next to Strasbourg

Strasbourg

Strasbourg is the capital and principal city of the Alsace region in eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...

 and the Souffel

Souffel

The Souffel is a river in Alsace, France. It rises near Kuttolsheim and joins the Ill river , south of La Wantzenau after a course of 26 km. It has given its name to two villages on its banks: Souffelweyersheim and Griesheim-sur-Souffel. Tributaries of the Souffel are Haltbach, Plaetzerbach,...

 upstream from La Wantzenau

La Wantzenau

La Wantzenau is a commune in the Bas-Rhin department in Alsace in north-eastern France.-Location:The town is located 12 km northeast of Strasbourg. It is the last village along the Ill river before it joins the Rhine a few kilometres downstream...

 before meeting with the Rhine downstream from Gambsheim

Gambsheim

Gambsheim is a commune in the Bas-Rhin department in Alsace in north-eastern France.It is adjacent to a river crossing into Germany that is favoured by southbound autoroute traffic wishing to avoid traffic delays around Strasbourg...

's lock

Lock (water transport)

A lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...

.

As the Ill arrives to the city of Mulhouse, most of its flow is derivated into a discharge channel leading to the Doller, protecting by this way the historical center of this town from flood

Flood

A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

s.

Flowing through the city of Strasbourg, the river forms part of the 17th century fortifications and passes through a series of locks and channels in the picturesque old town, including the Petite-France

Petite-France

Petite-France is an area in Strasbourg, Alsace, France.It is located on the Grande Île , where the river Ill splits up into a number of canals and cascades through a small area of medieval half-timbered houses and baroque sandstone buildings...

district, where its waters were once used to power mills and tanneries.