Great Echo

After Melkor and Ungoliant had destroyed the Two Trees and fled back to Middle-earth, they came to a narrow land running between the mountains and the sea north of the Firth of Drengist. There Ungoliant demanded the payment she had been promised, and began to consume the many jewels and gems that Melkor had brought out of Aman. Still he kept back the Silmarils, until in her fury Ungoliant enmeshed him with her webs, and Melkor let out an dreadful cry of anguish.

That cry echoed from the mountains and spread across the North, and was heard by the Balrogs lurking in Angband. They sped to their master's aid, and drove Ungoliant off. So Melkor escaped with the three Jewels of Fëanor, but he left a lasting legacy in the land of his struggle. The mountains running down its eastward border held the memory of his cry, so that any loud sound would reawaken that memory and fill the mountains with echoing voices crying out in pain.

Thus the land became known as Lammoth, the Great Echo, and its mountains were Ered Lómin, the Echoing Mountains. These strange properties were discovered some years later when Fëanor led his people ashore in the same region. Deciding to set fire to his ships, his followers filled the land with noise, and the Great Echo of the mountains was awakened. From this noise Melkor became aware of his enemy's approach, and sent an army of Orcs out against Fëanor and his people, an army that was defeated in the battle known as the Dagor-nuin-Giliath.