- "From Evereven's lofty hills
where softly silver fountains fall
his wings him bore, a wandering light,
beyond the mighty Mountain Wall."
- ― The Fellowship of the Ring, Many Meetings - Song of Eärendil
The Mountain Wall was a term that appears just once, in Bilbo's poem Eärendil was a mariner quoted above. The meaning is not completely certain, but it seems to describe the Pelóri, the Mountains of Defence that ranged along the eastern borders of Valinor.