Largest tributaries
The Oker is a river in Lower Saxony, Germany, that has historically formed an important political boundary. It is a left tributary of the River Aller, 128 km in length and runs in a generally northerly direction.
The Oker is a river in Lower Saxony, Germany, that has historically formed an important political boundary. It is a left tributary of the River Aller, 128 km in length and runs in a generally northerly direction.
