Eldor Lake was a large lake east of Ceris. The Gaena River emptied into it and the Edda River stemmed from it. The Âz Ragni River, the Edda River, Lake Eldor, the Gaena River, and Ardwen Lake form an inland waterway from the Dwarven city of Tarnag to the Elven city of Silthrim, in Du Weldenvarden.
Eragon, Saphira, and their companions spent a bit of time at this lake during their journey to Ellesméra. It was described as being "rough with small, jagged waves."[1]