The Große Aa is a 25 km long, right, eastern tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the River Ems

River Ems

The river name Ems may refer to:* Ems , a river in Germany and the Netherlands* River Ems , a river in the English counties of West Sussex and Hampshire...

 in western Lower Saxony

Lower Saxony

Lower Saxony is a German state situated in north-western Germany and is second in area and fourth in population among the sixteen states of Germany...

 (Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

).

It begins in the collective municipality of Freren, near the quarter of Overwater, at the confluence of the Deeper Aa and Ahe rivers. From there is flows through Lünne

Lünne

Lünne is a municipality in the Emsland district, in Lower Saxony, Germany....

 westwards to Hesselte, where it is joined by the Speller Aa

Speller Aa

Speller Aa is a river of Lower Saxony, Germany.-See also:*List of rivers of Lower Saxony...

. From there on it runs parallel to the Dortmund-Ems Canal

Dortmund-Ems Canal

The Dortmund–Ems Canal is a 269 km long canal in Germany between the inland port of the city of Dortmund and the sea port of Emden. The artificial southern part of the canal ends after 215 km at the lock of Herbrum near Meppen. From there, the route goes over a length of 45 km over...

 and discharges into the Ems 6 km south of Lingen, a few metres north of the mouth of the canal after the Gleesen locks.

See also: Aa River

Aa River

Aa River may refer to:* Aa River , a river in northern France* Aa River , a river in North Brabant, Netherlands* Aa of Weerijs, a river in North Brabant, Netherlands* Drentsche Aa, a river in Groningen, Netherlands...