Hidden City

When Turgon son of Fingolfin came to Middle-earth with the Exiles, he at first settled in the land of Nevrast on the coast, establishing a seat at Vinyamar beneath Mount Taras. A vision from Ulmo guided him inland, where he found a hidden tunnel through the mountains that led him to Tumladen, a wide green plain surrounded on all sides by the Echoriath, the Encircling Mountains.

In the middle of the plain of Tumladen stood a rocky hill, Amon Gwareth, and on that hill Turgon set about building a new city, concealed from the eyes of Morgoth by the mountains. After decades of work, the city was finished, and Turgon summoned all his people from Nevrast to find a new home there. The city had many names, but it was known most famously as the Hidden City of Gondolin.

Completed in I 116, the Hidden City remained concealed from friend and foe alike for centuries, and survived longer against Morgoth than any of the other Elf-realms of Beleriand. It was not until the sixth century of the First Age that its location was betrayed by Maeglin, and in I 510 Morgoth's forces attacked and overwhelmed it. A small band of survivors escaped the sack, led by Turgon's daughter Idril, Tuor, and their young son Eärendil.