Pelóri

The wall of the West

When the Valar abandoned Almaren and came to Aman, their first work was to raise a mountain wall along its eastern coast so that Melkor could not come at them again. The Pelóri were the highest mountains in the world, running in a great curve from the ice of the north near the Helcaraxë to the far south, and behind them lay Valinor. Their tallest peak was Taniquetil, on which Manwë set his throne, and toward the southern end stood Hyarmentir, whose height was not so guarded and by which Melkor and Ungoliant climbed into the Blessed Realm out of Avathar.

The range had one gap. When the Eldar came, the Valar cut the Calacirya through the mountains so that the light of the Two Trees could reach the coast of Eldamar and the Elves on the shore need not be parted entirely from the sea and the stars. In the mouth of that pass they raised the hill of Túna for the city of Tirion.

The Hiding of Valinor

After the Noldor went into exile the Valar changed the Pelóri. They lifted the mountains to a sheer and terrible height, so that their outer faces were dark, smooth and unclimbable, and no bird or foot could pass them except through the Calacirya, which they kept open for the sake of the faithful Eldar but filled with watchers. From that time the range was called the Mountains of Defence in earnest, and together with the Enchanted Isles and the Shadowy Seas it closed the Blessed Realm to Middle-earth for the whole of the First Age. Only Eärendil passed through the Calacirya afterwards, and later the Elves returning by the Valar's leave.

The Pelóri ran north to south along the whole eastern edge of Aman, with the narrow coastlands of Araman, Eldamar and Avathar between their feet and the sea. Taniquetil stood on the south side of the Calacirya; Hyarmentir was far to the south above Avathar. On their western side the mountains fell to the plains and woods of Valinor, and the city of Valmar and the mound of the Trees lay close beneath them near the pass.