Topic summary
River Anduin
Extracted from the Wikipedia article Geography of Middle-earth.
Lands to the South
Just to the South of both Fangorn and Isengard is the wide grassy land of the Riders of Rohan, who provide cavalry to its southerly neighbour, Gondor. The River Anduin passes the hills of Emyn Muil and the enormous rock statues of the Argonath and flows through the dangerous rapids of Sarn Gebir and over the Falls of Rauros into Gondor. Gondor's border with Rohan is the Ered Nimrais, the White Mountains, which run east–west from the sea to a point near the Anduin; at that point is Gondor's capital city, Minas Tirith.