A deep gorge in the White Mountains of Rohan, defended by the ancient fortress of the Hornburg and the long earthwork known as Helm's Dike. Named after Helm Hammerhand, ninth king of Rohan, who defended it during the Dunlending wars. During the War of the Ring, Theoden's forces make their stand here against Saruman's army of Uruk-hai and Dunlendings in one of the war's most desperate engagements.