The Rethi River (रेथि नदी) is the largest river in the world by discharge volume, and one of the longest rivers on Abmarah in general. It flows in an almost straight west-to-east direction from the Km’mala Peaks to the Ashfall Sea, dividing Eqos in half. It is used as the boundary between the Kav’orra Desert and the Edeni Expanse & Vyzum Wastes. Similarly, it marks the border between the Zaaba Hukumat and the Calamity Covenant in the modern day, although the Hukumat has often controlled the lands south of the river historically. 

The Rethi Riverbank has been a cradle of civilization for thousands of years, supporting many kingdoms and cities over its history. While it has countless towns and smaller cities along its length such as Kaitzur and Nubarii, it is most well known for the two legendary cities that sit on opposite ends of the river: Kasaaq at the mouth of the Rethi, and Dibayad near the source. The Rethi River is considered sacred and holy within both Ashtadharma and the native eqosi religions, in part due to its floodplains irrigating extensive farmlands that feed the entire region. The river is often considered to be the bread-basket of the Kav’orra.