In J.R.R. Tolkien’s Middle-earth, Mount Doom is located in Mordor. The volcano, also called Orodruin in Tolkien’s invented languages, stands in the northeastern region of the Dark Lord Sauron’s realm.
Mount Doom is central to the history of the One Ring because Sauron forged the Ring there. Its fires are powerful enough to destroy the Ring, making the mountain the only practical destination for Frodo’s mission. The Fellowship’s journey therefore leads eastward toward Mordor rather than toward a conventional battlefield or royal city.
Mordor is enclosed by major mountain ranges, including the Ephel Dúath and the Ered Lithui. The land contains the Black Gate, Minas Morgul, the Tower of Cirith Ungol, and Barad-dûr, Sauron’s fortress.
Readers sometimes confuse Mordor with Gondor because the two lands face each other across the borderlands near Minas Tirith. Gondor is a neighboring kingdom; Mount Doom itself is within Mordor.