River Arrud (pronounced ah-ROOD) is a major river in Tamkaranu. It begins in the western side of the Kurzag Mountains where, joined by many tributaries in the foothills, it then flows out into the Chaska Sea. Water levels in the river vary widely throughout the year, with their highest levels in the spring and the lowest in late summer, as it is heavily dependent on rainfall in the otherwise rather arid mountains.
Tamkaranu's capital city, Nindara, sits at the mouth of River Arrud.