Dúath

Dúath is a term used in J. R. R. Tolkien’s legendarium to refer to a mountainous border in Middle-earth, most often associated with the western boundary of Mordor. In the most widely cited usage, Ephel Dúath, the Mountains of Shadow, forms Mordor’s western frontier and is sometimes simply called the Dúath in various manuscripts or quotations. The range runs roughly north–south along Mordor’s western edge, acting as a natural barrier between the dark plain of Mordor and the lands to the west.

The Dúath are described as stark, rugged, and foreboding, composed of dark rock and harsh terrain. Their reputation as a formidable obstacle is reinforced by the scarcity of navigable passes. The principal crossing through the Ephel Dúath is Cirith Ungol, a notable pass that leads into the region around Minas Morgul, and which plays a significant role in the events surrounding the Mount Doom narrative arc. Other gaps and faults exist but are seldom described in detail in the canonical texts.

Geographically, Mordor is bounded to the north by the Ered Lithui (the Ash Mountains) and to the west (in many sources) by the Ephel Dúath, underscoring Mordor’s isolation from surrounding realms. The Dúath, together with these neighboring ranges, helps define the inhospitable landscape that shapes Sauron’s fortifications and the strategic dynamics of the region in Tolkien’s works. The name itself derives from Sindarin, reflecting the linguistic conventions Tolkien used to name borders and borderlands.