When the Hidden City of Gondolin was built by Turgon, the eagles of Thorondor became his allies, bringing him news and keeping spies off the borders. Therefore the Orcs of Morgoth were unable to approach either the nearby mountains, or the important ford of Brithiach to the south; the eagles' watch had been redoubled after the coming of Tuor, enabling Gondolin to remain undiscovered the longest of all Elven realms. When the city fell at last, the eagles of Thorondor protected the fugitives, from the orcs that ambushed them at Cirith Thoronath north of Gondolin.