Yaruga (Polish: Jaruga), or Yarra to the Nilfgaardians, is the largest river in the Northern Kingdoms, beginning in the Blue Mountains and flowing westward all the way to the Great Sea. The kingdoms of Cintra and Verden are located at the mouth of the river.
Andrzej Sapkowski description Edit
"At present, the border between us and the South — dominated by Nilfgaard — is demarcated, as you can see, by the Yaruga River. It constitutes an obstacle which is practically insurmountable. It hardly ever freezes over, and during the rainy season it can carry so much water that its bed is almost a mile wide. For a long stretch it flows between precipitous, inaccessible banks, between the rocks of Mahakam..."
- - pg.269, Blood of Elves (UK edition)