|Location||Eastern Lands of Middle-earth, east of Mordor and Rhovanion|
|Description||East of Mordor and the Sea of Rhûn|
|Other names||The East|
|Etymology||S. rhûn "east"|
Far beyond the Sea of Rhûn was another inland sea, the Sea of Helcar, and beyond that the range of Orocarni, the Red Mountains. Somewhere in the lost east, too, lay Cuiviénen and Hildórien, where Elves and Men first awoke: all the Children of Ilúvatar could trace their ancestries back to the eastward regions of Middle-earth. We know also that it was a wide and vast land with many kingdoms, and strange and unexplored places.
Rhûn was the domain of the Easterlings, Men of Darkness who were ready to follow both the Dark Lords and fought as their allies in war. These lands, too, were peopled by lost Elves, Avari and Úmanyar, and by four of the seven clans of the Dwarves who dwelt in the Orocarni.
Rhûn was conquered by Gondor twice: under the Kings Rómendacil I and Rómendacil II, but the Númenóreans never had full control over it. Rhûn was finally subdued in the Fourth Age under King Elessar and his son Eldarion.
The western part of Rhûn is shown on the Lord of the Rings map. It contains the great Sea of Rhûn, connected with three rivers, one northeast, a part of River Running, one northwest and one running south to Mordor. It also shows a small mountain range southeast of the sea and a forest northwest of it. Northwest of the Sea of Rhûn lays also the land of Dorwinion.
The inland Sea of Rhûn was located in western Rhûn on the border between Rhûn and Wilderland. There were mountains on the southwest side of the Sea of Rhûn and a forest on the northeast side. Wild white Kine of Araw, or oxen, lived near the shores of the Sea of Rhûn.
- The Fellowship of the Ring: "The Council of Elrond", "The Breaking of the Fellowship"
- The Two Towers: "The Black Gate is Closed,"; "Of Herbs and Stewed Rabbit,"; "The Window on the West"
- Appendix A of The Lord of the Rings: "Gondor and the Heirs of Anarion", "The House of Eorl"
- The History of Middle-earth, vol. XII, The Peoples of Middle-earth: "The Heirs of Elendil,"; "The Tale of Years of the Third Age,"; "The Making of Appendix A,"; "Of Dwarves and Men,".