- The foundation of the Hornburg.A spur of rock that stood out southward from the northern rock-wall of Helm's Deep. It was on the crest of the Hornrock that the castle of the Hornburg was built, and from it the Deeping Wall ran across the Deep's mouth to the southern wall.
J.R.R. Tolkien's Middle-earth glossary. MueRTe. 2003.