The Amper, called the Ammer upstream of the Ammersee, through which it runs, is the largest tributary of the Isar in southern Bavaria, Germany.
It flows generally north-eastward, reaching the Isar in Moosburg, about 190 kilometres (120 mi) from its source in the Ammergau Alps, with a flow of 45 m³/s.
Including its tributary, Linder, it is 209.5 km (130.2 mi) long.
Major tributaries are the Glonn, which rises near Augsburg; the Würm, which is the outflow of Lake Starnberg; and the Maisach.

The Ammer starts just south of the village of Oberammergau.
Riverside cities include Fürstenfeldbruck, Dachau and Moosburg.
The Amper, called the Ammer upstream of the Ammersee, through which it runs, is the largest tributary of the Isar in southern Bavaria, Germany. It flows generally north-eastward, reaching the Isar in Moosburg, about 190 kilometres (120 mi) from its source in the Ammergau Alps, with a flow of 45 m³/s. Including its tributary, Linder, it is 209.5 km (130.2 mi) long. Major tributaries are the Glonn, which rises near Augsburg; the Würm, which is the outflow of Lake Starnberg; and the Maisach.
The Ammer starts just south of the village of Oberammergau. Riverside cities include Fürstenfeldbruck, Dachau and Moosburg.
Amper