The Echoriad, also known as the Encircling Mountains or the Mountains of Turgon, were a mountain range in the north of Beleriand.
Description
The Echoriad were part of the highlands around Dorthonion, with the Pass of Sirion separating them from the Ered Wethrin to the west; and the Pass of Anach separating them from the Ered Gorgoroth to the east. The southern part of the circle of mountains were called the Crissaegrim, which was the abode of eagles.
The Echoriad formed a natural circle of rock, enclosing the valley later called Tumladen, within which lay the Elven city of Gondolin. A hidden ravine called Orfalch Echor provided the main access through the Echoriath — a way guarded by the Seven Gates.
Maeglin prospected in the northern part of the Echoriad and found diverse and abundant metals. From his mine, Anghabar, he found hard iron that he prized.
When Fingolfin died in single combat with Morgoth, the eagle Thorondor carried his body to a mountaintop north of Gondolin. Turgon, the son of Fingolfin, came and built a cairn over his body that no Orc dared to approach. Also in the aftermath of the Dagor Bragollach, Húrin and Huor were the first men to enter Gondolin, but they did not traverse the hidden ravine to reach the city - instead they were borne aloft by the eagles of Thorondor over the Encircling Mountains. Later they departed in the same manner and thus could not reveal the passage into Tumladen.
Yet it was Húrin who, despite his oath, eventually and inadvertently revealed the location of Turgon's realm to Morgoth. Húrin came to the Encircling Mountains and, lost, cried out for Turgon to hear him in his hidden halls. Húrin was unaware that spies of Morgoth heard his words and reported to their master that the Hidden Kingdom must be located somewhere in this region.
Then, after Maeglin was captured and revealed the precise location of the city, the host of Morgoth came to Gondolin, pouring over the Echoriad from the north and north east. All would have died within the city, but Idril had made a secret tunnel. She and Tuor led the remnants of the people of Gondolin out by this route and then they climbed into the mountains to the north, by the perilous pass known as the Cirith Thoronath. The refugees were attacked by Orcs and a Balrog. While eagles dispersed the Orcs, Glorfindel fought with the Balrog upon a pinnacle of rock and both fell into the nearby abyss. Like he did with Fingolfin, Thorondor came and brought Glorfindel's body up to the refugees, who buried him in a mound of stones beside the path. The Exiles of Gondolin then proceeded with their escape, eventually coming out of the mountains and into the Vale of Sirion.