The Isen is a small river in southeast Upper Bavaria

Upper Bavaria

Upper Bavaria is one of the seven administrative regions of Bavaria, Germany.- Geography :Upper Bavaria is located in the southern portion of Bavaria, and is centered around the city of Munich. It is subdivided into four regions : Ingolstadt, Munich, Bayerisches Oberland , and Südostoberbayern...

 with a length of about 76 kilometres. The Isen rises near Lacken (in the municipality of Maitenbeth

Maitenbeth

Maitenbeth is a municipality in the district of Mühldorf in Bavaria in Germany....

, district of Mühldorf am Inn

Mühldorf (district)

Mühldorf is a district in Bavaria, Germany. It is bounded by the districts of Landshut, Rottal-Inn, Altötting, Traunstein, Rosenheim, Ebersberg and Erding.-History:...

) and flows through one of the most unspoiled regions of Old Bavaria (Altbayern): the Isen Valley.

First seeing the light of day in the district of Mühldorf, the waters of the Isen flow initially into the district of Erding

Erding (district)

Erding is a district in Bavaria, Germany. It is bounded by the districts of Landshut, Mühldorf, Ebersberg, Munich and Freising.-History:...

 the villages of Isen

Isen, Bavaria

Isen is a municipality in the district of Erding in Bavaria in Germany.Isen has once been home to a Benedictine abbey. The abbey was dissolved however during the secularisation in 1802 so only the St. Zeno Church remains today....

, Lengdorf

Lengdorf

Lengdorf is a municipality in the district of Erding in Bavaria in Germany....

 and Dorfen

Dorfen

Dorfen is a town in the district of Erding, in Bavaria, Germany. It is situated 18 km east of Erding and 29 km south of Landshut....

, and then return again to Mühldorf district coursing through (Schwindegg

Schwindegg

Schwindegg is a municipality in the district of Mühldorf in Bavaria in Germany....

, Ampfing

Ampfing

Ampfing is a municipality in the district of Mühldorf in Bavaria in Germany.- History :The Battle of Mühldorf was fought on September 28, 1322 between Bavaria and Austria in Ampfing Heath. The Bavarians were led by Louis the Bavarian, while the Austrians were led by his cousin Frederick I of Austria...

, Mettenheim

Mettenheim

Mettenheim is a municipality in the district of Mühldorf in Bavaria in Germany....

, Mühldorf am Inn and Erharting

Erharting

Erharting is a municipality in the district of Mühldorf in Bavaria in Germany....

). Finally it flows into the Inn

Inn River

The Inn is a river in Switzerland, Austria and Germany. It is a right tributary of the Danube and is approximately 500km long. The highest point of its drainage basin is the summit of Piz Bernina, at 4,049 metres.- Geography :...

 in the district of Altötting

Altötting (district)

Altötting is a district in Bavaria, Germany. It is bounded by Austria and the Bavarian districts of Traunstein, Mühldorf and Rottal-Inn.- History :...

, municipality Winhöring

Winhöring

Winhöring is a municipality in the district of Altötting in Bavaria in Germany.Winhöring is the starting point of the famous federal road 588 to Eggenfelden. No federal road in Germany has a higher reference number than this road. Winhöring also features a bewitched castle in the middle of a...

, opposite Neuötting

Neuötting

Neuötting is a town in the district of Altötting, in Bavaria, Germany. It is situated on the river Inn, 2 km north of Altötting, about 70 km north of Salzburg, 80 southwest of Passau and almost 100 km east of Munich. It is a stop on the railway line between Munich and Simbach.-Townscape:Neuötting...

.

The mouth of the Isen where it discharges into the Inn was moved further west to between the villages of Kronberg and Unterau in the municipality of Winhöring in the 19th century during the building of the München–Mühldorf–Simbach railway line

Mühldorf–Simbach am Inn railway

The Mühldorf–Simbach am Inn railway is a 39 km long, single-tracked, unelectrified main line in Bavaria in southern Germany.Leaving Mühldorf station it runs in an east-west direction to the German-Austrian state border, where it joins the Innviertel Railway. Until 1969 there was also a...

. Its original mouth was near the village of Kager. Even today a few marshy spots in the fields and meadows give away the old course of the Isen.

The Isen Valley, with its tributaries, is a Special Area of Conservation

Special Area of Conservation

A Special Area of Conservation is defined in the European Union's Habitats Directive , also known as the Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora...

 (Fauna-Flora-Habitat-Richtlinie or FFH) that is threatened by the construction of the A 94

Bundesautobahn 94

is an autobahn in southern Germany supposed to connect Munich with Passau at the Austrian border. However, due to ongoing objections against the proposed routing, only the parts Munich-Forstinning and Ampfing-Burghausen have been built so far.- Exit list :...

 motorway.

The water quality

Water quality

Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...

 of the Isen is moderately to critically polluted.
Its tributaries are the Lappach

Lappach

Lappach is a river of Bavaria, Germany.-See also:*List of rivers of Bavaria...

, Ornaubach, Kagnbach and Goldach

Goldach

Goldach is a municipality in the Wahlkreis of Rorschach in the canton of St. Gallen in Switzerland.-History:Goldach is first mentioned in 789 as Goldaha, though this comes from a later copy of the original document. In 847 it was mentioned as Coldaun.-Geography:Goldach has an area, , of...

.

TV Documentaries

• Die Isen. TV series Topographie by Dieter Wieland. Bayerischer Rundfunk 1981.
• Mein Isental. Nature documentary by Jan Haft. Bayerisches Fernsehen 2007. 45 min.