In J. R. R. Tolkien's fictional world of Middle-earth, Mordor (pronounced ˈmɔrdɔr; from Sindarin Black Land and Quenya Land of Shadow) is the realm and base of the evil Sauron. It lay to the east of Gondor and the great river Anduin, and to the south of Mirkwood. Mount Doom, a volcano in Mordor, was the goal of the Fellowship of the Ring in the quest to destroy the One Ring. Mordor was surrounded by three mountain ranges, to the north, the west, and the south. These both protected the land from invasion and kept those living in Mordor from escaping.
Commentators have noted that Mordor was influenced by Tolkien's own experiences in the industrial Black Country of the English Midlands, and by his time fighting in the trenches of the Western Front in the First World War. Another forerunner that Tolkien was very familiar with is the account of the monster Grendel's unearthly landscapes in the Old English poem Beowulf. Others have observed that Tolkien depicts Mordor as specifically evil, and as a vision of industrial environmental degradation, contrasted with either the homey Shire or the beautiful elvish forest of Lothlórien.
Mordor was roughly rectangular in shape, with the longer sides on the north and south. Three sides were defended by mountain ranges: the Ered Lithui ("Ash Mountains") on the north, and the Ephel Dúath on the west and south. The lengths of these ranges are estimated to be respectively, which gives Mordor an area of roughly .
To the west lay the narrow land of Ithilien, a province of Gondor; to the northwest, the Dead Marshes and Dagorlad, the Battle Plain; to the north, Wilderland; to the northeast and east, Rhûn; to the southeast, Khand; and to the south, Harad. Not far from the Dead Marshes is another dismal swamp, the Nindalf or Wetwang, beside the Emyn Muil hills.
In the northwest, the pass of Cirith Gorgor led into the enclosed plain of Udûn. Sauron built the Black Gate of Mordor (the Morannon) across the pass.