Deeping Coomb is the deep, well-defended valley in the northern White Mountains that held Helm's Deep and the castle of the Hornburg. The site of an important battle, the Battle of the Hornburg, during the War of the Ring. The word coomb is a rare Brythonic survival word (as in the Welsh cwm); meaning a small deep dry valley, easily defended. It gives its name to many places in the British Isles.
- Deeping Coomb at Tolkien Gateway