Anduin

From t2twiki

Anduin, the longest river in the third age. It begins with two streams near where the Misty Mountains and the Grey Mountains meets. It then flows south, through Rhovanion and passes the old ford at Rhosgobel. Further south as it flows, it comes to Lothlorien and then breaks of to southeast, where it flows through the Brown Lands at the north undeep and south undeep. It then reaches the Emyn Muil and after comes to the Falls of Rauros. From the falls, it flows into the Mouths of the Entwash and soon after, reaches the banks of northern Ithilien. It then flows through the ruined city of Osgiliath, then reaches the harbor of Harlond. Now the final destination is near, though before that it flows pass Pelargir and then enters the Mouths of the Anduin which is its final destination.