Hidden Gates

Turgon raised his city of Gondolin on the concealed plain of Tumladen, surrounded on all sides by the Encircling Mountains. After his people removed there, neither friend nor foe knew where the city lay. So it remained protected from Morgoth through centuries, while the Wars of Beleriand were fought beyond its mountain walls.

There was a way through the mountains to the city, but like the city itself the way was concealed. It followed the course of the Dry River, the empty bed of an ancient tributary of Sirion, which ran up to a dark opening at the feet of the cliffs of the Echoriath. This appeared to be a natural cavern, but a traveller entering the tunnel would soon encounter the Dark Guard who kept it protected. Within the tunnel was the Dark Gate, the first of the Hidden Gates that led through the Encircling Mountains.

There were seven of these gates in all (and indeed they are collectively known as the Seven Gates of Gondolin), built across the long, narrow ravine of the Orfalch Echor. Except for occasional secret messengers, the way was almost never used, but nonetheless it was strongly guarded against enemies. Each of the Seven Gates was made from a different material, and each was maintained by its own contingent of well-armed Elves.

After the Nirnaeth Arnoediad, in which the Elves were utterly defeated, Turgon withdrew into his city and increased its protection, going so far as the block the entranceway into the Orfalch entirely. However deeply concealed and strongly guarded they were, the Hidden Gates nonetheless failed to prevent the fall of Turgon's city. Its location was betrayed to Morgoth by Maeglin, whose armies ignored the gates and instead attacked by crossing the northern mountains. The city was overrun, and only a handful of survivors were able to escape, taking a secret route of their own through the mountains far from the Hidden Gates.