From A Wiki of Ice and Fire
The Skahazadhan is a major river of Essos. It begins in the southeastern Dothraki sea and flows southwest through Meereen into Slaver's Bay. South of the river are Lhazar and the red waste. Cities on its tributaries include Vaes Mejhah, Krazaaj Has, and Kosrak. A tributary also flows through the Khyzai Pass near Meereen. The Skahazadhan is a slow river with brown water.