The Anduin River System
The River Anduin (The Great River) begins in the northern part of the Misty Mountains runs for hundreds of miles southwards through Middle-earth on the east side of the Misty Mountains, until it reaches the sea at the Bay of Belfalas. The Anduin's major tributaries include: Celebrant, Erui, Gladden, Greylin, Limlight, Morgulduin, Onodlo, Poros, Sirith. The River Langwell and the Greylin are the source of the Anduin. The Old Ford is where the Old Forest Road crosses of the River Anduin about forty miles downriver from the Carrock. In older times, the river was crossed by a stone bridge here, but by the end of the Third Age, the bridge had long since disappeared, and the crossing is now no more than a simple ford.
The River Celebrant (Silverlode) begins in Kheled-zaram in the Dimrill Dale then flows southeastwards out of the valley of Nanduhirion, passing eastwards through the land of Lorien to meet the Great River, Anduin.
Deeping-Stream begins in the gorge of the White Mountains known as Helm's Deep. It flows through a culvert in the wall that guarded that refuge of the Rohirrim, and then around the feet of the rock where the Hornburg stood, before beginning its journey into the wide lands of Rohan and eventually emptying into the Onodlo.
Dimrill Stair is a sequence of waterfalls that lead down into the lake of Kheled-zaram. The Dimril Stair is also the southeastern part of the Redhorn Pass, leading down into Nanduhirion, the Dimrill Dale.
The River Erui begins in the White Mountains and flows southward through Lossarnach, to meet the River Anduin above Pelargir.
Ethir Anduin (Mouths of Anduin) is the wide estuary delta of the River Anduin, where it flows out into the Bay of Belfalas.
Gladden Fields are the marshlands that form where the Gladden River flows down out of the Misty Mountains and into the Great River Anduin. This was the site of Isildur's loss of the One Ring in the first years of the Third Age
The Gladden River (River of Golden Flowers) begins in the eastern Misty Mountains north of Khazad-dum, roughly halfway between the Carrock to the north and Lorien to the south, and flows a hundred miles eastward to the River Anduin at Gladden Fields. History has it that Smeagol (Gollum) acquired the One Ring from Deagol near the mouths of the Gladden. Ruins of two cities are located upstream from Gladden Fields. The elves refer to this river as Sir Ninglor, which roughly translates Goldwater River.
The River Greylin is one of the two sources for the River Anduin, which begins in the western Grey Mountains. The Greylin flows southwestward to meet the Langwell and form the source of the River Anduin
Kheled-zaram (The shimmering Mirrormere) This lake lies in the eastern valleys of the Misty Mountains and is probably the source of the Celebrant River.
The River Langwell is one of the sources of the Great River, Anduin, which begins in the western Grey Mountains.
The River Limlaith (Limlight) flows out of the northern parts of Fangorn Forest and continues eastward to join the Anduin at the Field of Celebrant. The Limlaith forms the northern border of Rohan.
The Mering Stream flows from beneath the Halifirien to join the River Onodlo. It forms part of Rohan's eastern border with Gondor.
The Morgulduin Stream flows out of the valley of Imlad Morgul, and past the gates of Minas Morgul, before passing southwestward through Ithilien and out into the River Anduin.
Nen Hithoel (Mist Cool Water) is the great oval lake that lies in the mid-course of the River Anduin, the Gates of Argonath are to the north and the rushing falls of Rauros are some twenty miles to the south. The gray stony hills of the Emyn Muil surround the lake. Two famous hills lie at its southern end, the famous Amon Hen and Amon Lhaw, the Hills of Sight and Hearing. Also near its southern end is the lake's only island, named Tol Brandir in Elvish, that Men call the Tindrock. Its steep rocky sides make landing on the island nearly impossible, and legend has it that no Man has ever stood on the Isle.
River Nimrodel begins in the eastern foothills of the Misty Mountains, and flows east to meet the Celebrant on the western borders of Lorien. This river is the setting of a folktale about a lost Elf-maiden.
The River Onodlo (Entwash) flows south through the land of Rohan until it joins its tributary, the Snowbourn River out of the White Mountains. From that point it flows east until it meets the Anduin at the Mouths of Onodlo below Rauros. Onodlo begins in the southern Misty Mountains within the Fangorn Forest. Its major tributaries include: Deeping-Stream, Snowbourn and Mering Stream. This river has a habit of overflowing its banks during the spring runoff. The Mouths of Onodlo (Entwash Delta) is the large delta formed where the River Onodlo meets the River Anduin. The delta spans a hundred miles from where the Onodlo fist splits and to where it dumps into the Anduin. On the eastern side of the River Anduin, opposite of the Mouths of Onodlo a marshland formed called Nindalf, or Wetwang in the Westron tongue.
The River Poros begins in the Ephel Duath on the borders of Mordor, and flows westwards to meet the Anduin above its mouth. The river marks the southern border-river of Ithilien. Ethir Anduin is the name of the fifty-mile wide Poros delta. This is a border region of Gondor, populated mainly by fishermen. The Crossing of Poros is the ford where the Harad Road crosses the River Poros. This was the site of a battle in the late Third Age in which Steward Turin II of Gondor and King Folcwine of Rohan defeated a force of the Haradrim
Rauros Falls are beneath the Nen Hithoel and drop from the heights of the Emyn Muil into the wetlands of the Nindalf.
The River Sirith begins in the White Mountains in eastern Lebennin, and flows southward, at which point it meets the Great River Anduin, at the port of Pelargir.
The Snowbourn River begins beneath the Starkhorn in the northern White Mountains and flows out of Harrowdale and past the courts of Edoras. It continues in Rohan north and east to meet the River Entwash among the grassy plains of Eastfold.
Undeep (North and South) are the two westward loops in the Anduin's course. The North Undeep is where the Anduin flows past the southern end of the Field of Celebrant, and on towards the northern fields of Rohan, a sudden pronounced westward loop in its course, into which the River Limlight flows. The South Undeep is the meander further south.
Bay of Belfalas is the bay into which the River Anduin flows. The Bay of Belfalas lies to the south of Gondor, within whose waters stood the island of Tolfalas.