Anduin

Anduin was the Sindarin name for the Great River of Wilderland, also known as the Great River, and to the Éothéod, ancestors of the Rohirrim, as the Langflood.
It was the longest river in the Third Age. In The Atlas of Middle-earth, Karen Wynn Fonstad estimates a total length of 1,388 miles (approximately 2,234 kilometers). The original Sindarin name means "Long River".
== Geography ==
The Anduin began as two different streams to the northwest of Mirkwood. These were called the Langwell and the Greylin by the Éothéod when they lived in the triangle of land formed by it. The Langwell had its source in the Misty Mountains, close to Mount Gundabad, and the Greylin began in the westernmost heights of the Grey Mountains. It flowed from these sources to the Mouths of Anduin in the Great Sea (Belegaer).
=== Course ===
The Anduin flowed parallel to the Misty Mountains in a broad vale which formed the western part of Rhovanion, lying between the mountains and Mirkwood. Passing the Carrock and Old Ford, the river reached Lórien, after which it left the mountains and flowed through the Brown Lands via the North and South Undeeps until it flowed past the Emyn Muil. After passing Sarn Gebir (a series of ferocious rapids) and the Argonath, it flowed into the lake of Nen Hithoel. Thence it flowed over the Falls of Rauros and past both the Mouths of Entwash and the marshes known as the Wetwang. It then passed between the White Mountains and the Mountains of Shadow by the capital of Gondor, Osgiliath, before passing close to the harbour of Harlond and the Rammas Echor south of Minas Tirith (Barbara Strachey, in Journeys of Frodo, places the harbour just outside the wall), and the Emyn Arnen and down past the port of Pelargir, entering the Great Sea in the Bay of Belfalas in a broad delta known as the Mouths of Anduin.
=== Tributaries ===
In order from north to south, the tributaries of the Anduin were: the Rushdown, the Gladden, which joined at the marshes known as the Gladden Fields, the Celebrant, the River Limlight, the Entwash, the Morgulduin, the Erui, the Sirith and the Poros. The first five had their sources in the Misty Mountains, the Morgulduin and the Poros in the Ephel Dúath on the border of Mordor, and the rest in the White Mountains.
=== Crossing points ===
The most northerly crossing point was the Ford of Carrock, held by the Beornings who levied high tolls on those passing in exchange for keeping the vale of the river free of Orcs.
The Old Forest Road which led from the High Pass into Mirkwood crossed the river at the Old Ford, to the south of Beorn's Hall.
The North and South Undeeps were two defiles where the river could be crossed. The Balchoth passed this way during their invasion of Calenardhon.
The river could be easily crossed (possibly with boats) at Cair Andros.
There were bridges in the city of Osgiliath. The Great Bridge was broken in TA 2475 and the last was broken by the forces of Gondor in TA 3018 to halt Mordor's attack on Osgiliath, but were later partly repaired by Mordor in the War of the Ring.
A road led from Pelargir to the Crossings of Poros, indicating either a bridge, a ferry crossing or a ford.
There were also two bypasses; a portage way around the rapids at Sarn Gebir and the North Stair beside the Falls of Rauros.
=== Islands ===
The principal islands of the river were Cair Andros, on the borders of Ithilien, and Tol Brandir in Nen Hithoel. Carrock, in the north, was where the eagles deposited Thorin and Company. There was also an eyot at which the Fellowship rested during their travel between Lórien and Parth Galen.
== Settlements ==
During the March of the Elves in the Time of the Trees, the Nandor left the Eldarin host when faced with the great heights of the Misty Mountains, and lived in the Vales of Anduin. Some of those people later left and became the Green-elves of Ossiriand, but Silvan Elves remained present even until the time of the War of the Ring, strengthen by refugees from Beleriand (at the end of the First Age) and Eregion (during the Second).
Settlements in the Vales of Anduin during the Third Age included the Northman city of Framsburg, Beorn's Halls, and the Stoor settlements near the Gladden Fields (where Sméagol/Gollum) was born. It was in the Gladden Fields in the northern reaches of Anduin that Isildur was slain and the One Ring lost; and it was there, more than two millennia later, that Déagol found the Ring and Sméagol took it from him. Rhosgobel, home of Radagast the Brown, and the Elven Realm of Lothlórien also lay in the Vale of Anduin.
Once it had entered Gondor, the river flowed through Osgiliath and past Minas Tirith and then Pelargir, close to the sea. After the fall of East Osgiliath in TA 3018 the river effectively marked the eastern limit of Gondor's influence.